Metal Industry Glossary

 


A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Backer Coat

Usually refers to the coating on the reverse side of a prepainted sheet. The backer coating is generally not as narrowly specified with reference to its color, thickness and composition as is the topcoat.

Bainite

A slender, needle-like (acicular) microstructure appearing in spring steel strip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite (see Austenite) best developed at interrupted holding temperatures below those forming fine pearlite and above those giving Martensite.

Band Saw Steel (Wood)

A hardened tempered bright polished high carbon cold rolled spring steel strip produced especially for use in the manufacture of band saws for sawing wood, non ferrous metals, and plastics. Usually carries some nickel and with a Rockwell value of approximately C40/45.

Banded Structure

Appearance of a metal, under a microscope or viewed by the naked eye, on fractured or moothed surfaces, with or without etching, sHowing parallel bands in the direction of rolling or working.

Bark

Surface of metal, under the oxide-scale layer, resulting from heating in an oxidizing environment. In the case of steel, such bark always suffers from decarburization.

Bars

Long steel products that are rolled from billets. Merchant bar and reinforcing bar (rebar) are two common categories of bars, where merchants include rounds, flats, angles, squares, and channels that are used by fabricators to manufacture a wide variety of products such as furniture, stair railings, and farm equipment. Rebar is used to strengthen concrete in highways, bridges and buildings (see Sheet Steel).

Basic Oxygen Process

A steel making process wherein oxygen of the highest purity is blown onto the surface of a bath of molten iron contained in a basic lined and ladle shaped vessel. The melting cycle duration is extremely short with quality comparable to Open Hearth Steel.

Basic Oxygen Furnace (BOF)

WHAT A pear-shaped furnace, lined with refractory bricks, that refines molten iron from the blast furnace and scrap into steel. Up to 30% of the charge into the BOF can be scrap, with hot metal accounting for the rest.
WHY BOFs, which can refine a heat (batch) of steel in less than 45 minutes, replaced open-hearth furnaces in the 1950s; the latter required five to six hours to process the metal. The BOF's rapid operation, lower cost and ease of control give it a distinct advantage over previous methods.
HOW Scrap is dumped into the furnace vessel, followed by the hot metal from the blast furnace. A lance is lowered from above, through which blows a high-pressure stream of oxygen to cause chemical reactions that separate impurities as fumes or slag. Once refined, the liquid steel and slag are poured into separate containers.

Basic Oxygen Process

A steel making process wherein oxygen of the highest purity is blown onto the surface of a bath of molten iron contained in a basic lined and ladle shaped vessel. The melting cycle duration is extremely short with quality comparable to Open Hearth Steel.

Basic Process

A steel making process either Bessemer, open hearth or electric, in which the furnace is lined with a basic refractory. A slag, rich in lime, being formed and phosphorous removed.

Basic Steel

Steel melted in a furnace with a basic bottom and lining and under a slag containing an excess of a basic substance such as magnesia or lime.

Bessemer Process

A process for making steel by blowing air through molten pig iron contained in a refractory lined vessel so that the impurities are thus removed by oxidation.

Bath Annealing

Immersion in a liquid bath (such as molten lead or fused salts) held at an assigned temperature. When a lead bath is used, the process is known as lead annealing.

Bauxite

The only commercial ore of aluminum, corresponding essentially to the formula Al2O3xH2O.

Beading

Raising a ridge on sheet metal.

Bend Text

Various tests used to determine the toughness and ductility of flat rolled metal sheet, strip or plate, in which the material is bent around its axis or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. For testing, samples should be edge filed to remove burrs and any edgewise cracks resulting from slitting or shearing. If a vice is to be used then line the jaws with some soft metal or brass, so as to permit a free flow of the metal in the sample being tested.

Beryllium Copper

An alloy of copper and 2-3% beryllium with optionally fractional percentages of nickel or cobalt. Alloys of this series sHow remarkable age-hardening properties and an ultimate hardness of about 400 Brinell (Rockwell C43). Because of such hardness and good electrical conductivity, beryllium-copper is used in electrical switches, springs, etc.

Bessemer Process

A steel making process in which air is blown through the molten iron so that the impurities are thus removed by oxidation.

Billet

A semi-finished steel form that is used for "long" products: bars, channels or other structural shapes. A billet is different from a slab because of its outer dimensions; billets are normally two to seven inches square, while slabs are 30-80 inches wide and 2-10 inches thick. Both shapes are generally continually cast, but they may differ greatly in their chemistry.

Binary Alloy

An alloy containing two elements, apart from minor impurities, as brass containing the two elements copper and zinc.

Black Annealing

A process of box annealing or pot annealing ferrous alloy sheet, strip or wire after hot working and pickling. (See Box Annealing)

Black Oil Tempered Spring Steel Strip (Scaleless Blue)

A flat cold rolled usually .70/.80 medium high carbon steel strip, blue-black in color, which has been quenched in oil and drawn to desired hardness. While it looks and acts much like blue tempered spring steel and carries a Rockwell hardness of C44/47, it has not been polished and is lower in carbon content. Used for less exacting requirements than clock spring steel, such as snaps, lock springs, hold down springs, trap springs, etc. It will take a more severe bend before fracture than will clock spring, but it does not have the same degree of spring-back.

Black Plate

Cold-reduced sheet steel, 12-32 inches wide, that serves as the substrate (raw material) to be coated in the tin mill.

Blanking

An early step in preparing flat-rolled steel for use by an end user. A blank is a section of sheet that has the same outer dimensions as a specified part (such as a car door or hood) but that has not yet been stamped. Steel processors may offer blanking for their customers to reduce their labor and transportation costs; excess steel can be trimmed prior to shipment.

Blast Box

(See Tin Plate Base Box)

Blast Furnace

A towering cylinder lined with heat-resistant (refractory) bricks, used by integrated steel mills to smelt iron from its ore. Its name comes from the "blast" of hot air and gases forced up through the iron ore, coke and limestone that load the furnace.

Blister

A defect in metal produced by gas bubbles either on the surface or formed beneath the surface while the metal is hot or plastic. Very fine blisters are called “pin-head” or “pepper” blisters.

Blister Steel

High-carbon steel produced by carburizing wrought iron. The bar, originally smooth, is covered with small blisters when removed from the cementation (carburizing) furnace.

Bloom

A semi-finished steel form whose rectangular cross-section is more than eight inches. This large cast steel shape is broken down in the mill to produce the familiar I-beams, H-beams and sheet piling. Blooms are also part of the high-quality bar manufacturing process: Reduction of a bloom to a much smaller cross-section can improve the quality of the metal.

Blooming-Mill

A mill used to reduce ingots to blooms, billets, slabs, sheet-bar etc. (See Semi-Finished Steel)

Blowhole

A cavity produced during the solidification of metal by evolved gas, which in failing to escape is held in pockets.

Blue Annealing

A process of softening ferrous alloys in the form of hot rolled sheet, by heating in the open furnace to a temperature within the transformation range and then cooling in air. The formation of bluish oxide on the surface is incidental.

Blue Brittleness

Brittleness exhibited by some steels after being heated to some temperature within the range of 300 (degrees) to 650 (degrees) F, and more especially if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness.

Blue Tempered Spring Steel Strips

(See Tempered Spring Steel Strip)

Bluing

1) Sheets - A method of coating sheets with a thin, even film of bluish-black oxide, obtained by exposure to an atmosphere of dry steam or air, at a temperature of about 1000 0øF., generally this is done during box-annealing.
2) Bluing of tempered spring steel strip; an oxide film blue in color produced by low temperature heating.

Body-Centered

(Concerning space lattices.) Having the equivalent lattice points at the corners of the unit cell, and at its center; sometimes called centered or space-centered.

Bonderizing

The coating of steel with a film composed largely of zinc phosphate in order to develop a better bonding surface for paint or lacquer.

Boron

(Chemical Symbol B)- Element No. 5 of the periodic system. Atomic weight 10.82. It is gray in color, ignites at about 1112°F. and burns with a brilliant green flame, but its melting point in a non-oxidizing atmosphere is about 4000°F. Boron is used in steel in minute quantities for one purpose only - to increase the hardenability as in case hardening and to increase strength and hardness penetration.

Bottle Top Mold

Ingot mold, with the top constricted; used in the manufacture of capped steel, the metal in the constriction being covered with a cap fitting into the bottle-neck, which stops rimming action by trapping escaping gases.

Bow

(See Camber)

Box Annealing

A process of annealing a ferrous alloy in a suitable closed metal container, with or without packing materials, in order to minimize oxidation. The charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly. This process is also called “close annealing” or “pot annealing.” (See Black Annealing)

Brake

A piece of equipment used for bending sheet: also called a “bar folder.” If operated manually, it is called a “hand brake”; if power driven, it is called a “press brake.”

Brale

A diamond penetrator, conical in shape, used with a Rockwell hardness tester for hard metals.

Brass (Cartridge)

Strip. 70% copper 30% zinc. This is one of the most widely used of the copper-zinc alloys; it is malleable and ductile; has excellent cold-working; poor hot working and poor machining properties; develops high tensile strength with cold-working. Temper is impaired by cold rolling and classified in hardness by the number of B & S Gages of rolling (reduction in thickness) from the previous annealing gage. Rated excellent for soft-soldering; good for silver alloy brazing or oxyacetylene welding and fair for resistance of carbon arc welding. Used for drawn cartridges, tubes, eyelet machine items, snap fasteners, etc.

Brass Shim

(See Shim)

Brass (Yellow)

Strip. 65% copper and 35% zinc. Known as “High Brass” or “Two to One Brass.” A copper-zinc alloy yellow in color. Formerly widely used but now largely supplanted by Cartridge Brass.

Brasses

Copper base alloys in which zinc is the principal added element. Brass is harder and stronger than either of its alloying elements copper or zinc; it is malleable and ductile; develops high tensile with cold-working and not heat treatable for purposes of hardness development.

Brazing

Joining metals by fusion of nonferrous alloys that have melting points above 800°F. but lower than those of the metals being joined. This may be accomplished by means of a torch (torch brazing), in a furnace (furnace brazing) or by dipping in a molten flux bath (dip or flux brazing). The filler metal is ordinarily in rod form in torch brazing; whereas in furnace and dip brazing the work material is first assembled and the filler metal may then be applied as wire, washers, clips, bands, or may be integrally bonded, as in brazing sheet.

Break Test (for tempered steel)

A method of testing hardened and tempered high carbon spring steel strip wherein the specimen is held and bent across the grain in a vice-like calibrated testing machine. Pressure is applied until the metal fractures at which point a reading is taken and compared with a standard chart of brake limitations for various thickness ranges.

Breakout

An accident caused by the failure of the walls of the hearth of the blast furnace, resulting in liquid iron or slag (or both) flowing uncontrolled out of the blast furnace.

Bridling

The cold working of dead soft annealed strip metal immediately prior to a forming, bending, or drawing operation. A process designed to prevent the formulation of Luder’s lines. Caution: Bridled metal should be used promptly and not permitted to (of itself) return to its pre-bridled condition.

Bright Annealing

A process of annealing usually carried out in a controlled furnace atmosphere so that surface oxidation is reduced to a minimum and the surface remains relatively bright.

Bright Annealed Wire

Steel wire bright drawn and annealed in controlled non-oxidizing atmosphere so that surface oxidation is reduced to a minimum and the surface remains relatively bright.

Bright Basic Wire

Bright steel wire, slightly softer than Bright Bessemer Wire. Used for round head wood screws, bolts and rivets, electric welded chain, etc.

Bright Bessemer Wire

Stiff bright steel wire of hard drawn temper. Normally drawn to size without annealing. Used for nails, flat head wood screws, cheap springs, etc.

Bright Commercial Finish

(See Finish)

Bright Dip

An acid solution into which articles are dipped to obtain a clean, bright surface.

Brinell Hardness (Test)

A common standard method of measuring the hardness of certain metals. The smooth surface of the metal is subjected to indentation by a hardened steel ball under pressure or load. The diameter of the resultant indentation, in the metal surface, is measured by a special microscope and the Brinell hardness value read from a chart or calculated formula.

Brittleness

A tendency to fracture without appreciable deformation.

Broaching

Multiple shaving, accomplished by pushing a tool with stepped cutting edges along the work, particularly through holes.

Bronze

Primarily an alloy of copper and tin but the name is now applied to other alloys not containing tin; e.g., aluminum, bronze, manganese bronze, and beryllium bronze. For varieties and uses of tin bronze see (Alpha Bronze and Phosphor Bronze).

Brown & Sharpe Gages (B & S)

A standard series of sizes arbitrarily indicated, as by numbers, to which the diameter of wire or thickness of sheet metal is usually made and which is used in the manufacture of brass, bronze, copper, copper-base alloys and aluminum. These gage numbers have a definite relationship to each other. By this system the decimal thickness is reduced by 50% every six gage numbers -while temper is expressed by the number of B S gage numbers as cold reduced in thickness from previous annealing. For each B & S gage number in thickness reduction, there is assigned a hardness value of ¼ hard. To illustrate: One number hard = ¼ hard, two numbers hard = ½ hard, etc.

Buckle

Alternate bulges or hollows recurring along the length of the product with the edges remaining relatively flat.

Burning

Heating a metal beyond the temperature limits allowable for the desired heat treatment, or beyond the point where serious oxidation or other detrimental action begins.

Burnt

A term applied to a metal permanently damaged by overheating.

Burr

The very subtle ridge on the edge of strip steel left by cutting operations such as slitting, trimming, shearing, or blanking. For example, as a steel processor trims the sides of the sheet steel parallel or cuts a sheet of steel into strips, its edges will bend with the direction of the cut (see Edge Rolling).

Busheling

Steel scrap consisting of sheet clips and stampings from metal production. This term arose from the practice of collecting the material in bushel baskets through World War II.

Butcher Saw Steel

A hardened, tempered, and bright polished high carbon spring steel strip (carbon content a bit higher than in wood band saw quality) with a Rockwell value of approximately C47/49.

Butt Welting

Joining two edges or ends by placing one against the other and welding them.

Butt-Weld Pipe

The standard pipe used in plumbing. Heated skelp is passed continuously through welding rolls, which form the tube and squeeze the hot edges together to make a solid weld.

Back to Top

Cake

A copper ingot rectangular in cross section intended for rolling.

Camber

Edgewise curvature. A lateral departure of a side edge of sheet or strip metal from a straight line.

Camera Shutter Steel

Hardened, tempered and bright polished extra flat and extra precision rolled. Carbon content 1.25 - Chromium .15.

Capacity

Normal ability to produce steel in a given time period. This rating should include maintenance requirements, but because such service is scheduled to match the needs of the machinery (not those of the calendar), a mill might run at more than 100% of capacity one month and then fall well below rated capacity as maintenance is performed.
ENGINEERED CAPACITY The theoretical volume of a mill, given its constraints of raw material supply and normal working speed.
"TRUE" CAPACITY Volume at full utilization, allowing for the maintenance of equipment and reflecting current material constraints. (Bottlenecks of supply and distribution can change over time, capacity will expand or reduce.)

Capped Steel

Semikilled steel cast in a bottle-top mold and covered with a cap fitting into the neck of the mold. The cap causes to top metal to solidify. Pressure is built up in the sealed-in molten metal and results in a surface condition much like that of rimmed steel.

Carbide

A compound of carbon with one or more metallic elements.

Carbon

(Chemical symbol C) - Element No. 6 of the periodic system; atomic weight 12.01; has three allotropic modifications, all non-metallic. Carbon is preset in practically all ferrous alloys, and has tremendous effect on the properties of the resultant metal. Carbon is also an essential compound of the cemented carbides. Its metallurgical use, in the form of coke, for reduction of oxides, is very extensive.

Carbon Free

Metals and alloys which are practically free from carbon.

Carbon Range

In steel specifications, the carbon range is the difference between the minimum and maximum amount of carbon acceptable.

Carbon Steel

A steel containing only residual quantities of elements other than carbon, except those added for deoxidization or to counter the deleterious effects of residual sulfur. Silicon is usually limited to about 0.60% and manganese to about 1,65%. Also termed plain carbon steel, ordinary steel, straight carbon steel.

Carburizing

(Cementation) Adding carbon to the surface of iron-base alloys by absorption through heating the metal at a temperature below its melting point in contact with carbonaceous solids, liquids or gasses. The oldest method of case hardening.

Case Hardening

Hardening a ferrous alloy so that the outer portion, or case, is made substantially harder than the inner portion, or core. Typical processes used for case hardening are carburizing, cyaniding, carbonitriding, nitriding, induction hardening, and flame hardening.

Case Hardening

A generic term covering several processes applicable to steel that change the the chemical composition of the surface layer by absorption of carbon or nitrogen, or a mixture of the two, and, by diffusion, create a concentration gradient.

Casing

Casing is the structural retainer for the walls of oil and gas wells, and accounts for 75% (by weight) of OCTG shipments. Casing is used to prevent contamination of both the surrounding water table and the well itself. Casing lasts the life of a well and is not usually removed when a well is closed.

Cast

1) A term indicating in the annealed state as Cast Spring Steel Wire.
2) In reference to Bright or Polished Strip Steel or Wire, the word cast implies discoloration as a shadow.
3) A term implying a lack of straightness as in a coil set.

Cast Iron

Iron containing more carbon than the solubility limit in austenite (about 2%).

Cast Steel

Steel in the form of castings, usually containing less than 2% carbon.

Cementite

A compound of iron and carbon, known chemically as iron carbide and having the approximate chemical formula Fe3C. It is characterized by an orthorhombic crystal structure. When it occurs as a phase in steel, the chemical composition will be altered by the presence of manganese and other carbide-forming elements.

Charcoal Tin Plate

Tin Plate with a relatively heavy coating of tin (higher than the “Coke Tin Plate” grades).

Charge

The act of loading material into a vessel. For example, iron ore, coke and limestone are charged into a Blast Furnace; a Basic Oxygen Furnace is charged with scrap and hot metal.

Chatter Marks

(Defect) - Parallel indentations or marks appearing at right angles to edge of strip forming a pattern at close and regular intervals, caused by roll vibrations.

Chemical Treatment

An aqueous solution of corrosion-inhibiting chemicals, typically chromates or chromate/phosphate.

Chipping

A method for removing seams and surface defects with chisel or gouge so that such defects will not be working into the finished product. Chipping is often employed to remove metal that is excessive but not defective. Removal of defects by gas cutting is known as “deseaming” or “scarfing.”

Chromium (Cr)

An alloying element that is the essential stainless steel raw material for conferring corrosion resistance. A film that naturally forms on the surface of stainless steel self-repairs in the presence of oxygen if the steel is damaged mechanically or chemically, and thus prevents corrosion from occurring.

Chromium-Nickel Steel

Steel usually made by the electric furnace process in which chromium and nickel participate as alloying elements. The stainless steel of 18% chromium and 8% nickel are the better known of the chromium-nickel types.

Cigarette Knife Steel

Hardened, tempered and bright polished, 1.25 Carbon content- Chromium .15. Accurate flatness necessary and a high hardness with Rockwell C 51 to 53. Usual sizes are 4 3/4 wide and 6 wide x .004 to .010.

Circored®

WHAT A gas-based process developed by Lurgi Metallurgie in Germany to produce DRI or HBI (see Direct Reduced Iron and Hot Briquetted Iron).
HOW The two-stage method yields fines with a 93% iron content. Iron ore fines pass first through a circulating fluidized-bed reactor, and subsequently through a bubbling fluidized-bed reactor.

Cladding

WHAT Method of applying a stainless steel coating to carbon steel or lower-alloy steel (i.e., steel with alloying element content below 5%).
WHY To increase corrosion resistance at lower initial cost than exclusive use of stainless steel.
HOW By (1) welding stainless steel onto carbon steel, (2) pouring melted stainless steel around a solid carbon steel slab in a mold, or (3) placing a slab of carbon steel between two plates of stainless steel and bonding them by rolling at high temperature on a plate mill.

Clad Metal

A composite metal containing two or three layers that have been bonded together. The bonding may have been accomplished by co-rolling, welding, heavy chemical deposition or heavy electroplating.

Cluster Mill

A rolling mill where each of the two working rolls of small diameter is supported by two or more back-up rolls.

Cobalt

(Chemical symbol Co.) Element No. 27 of the periodic system; atomic weight 58.94. A gray magnetic metal of medium hardness; it resists corrosion like nickel, which it resembles closely; melting point 2696°F.; boiling point about 5250°F.; specific gravity 8.9. It is used as the matrix metal in most cemented carbides and is occasionally electroplated instead of nickel, the sulfate being used as electrolyte. Its principal function as an alloy in tool steel; it contributes to red hardness by hardening ferrite.

Coil or Longitudinal Curl

A lengthwise curve or set found in coiled strip metals following its coil pattern. A departure from longitudinal flatness. It can be removed by roller or stretcher leveling from metals in the softer temper ranges.

Coil Breaks

Creases or Ridges appearing in sheets as parallel lines transverse to the direction of rolling and generally extending across the width of the sheet.

Coil Weld

A joint between two lengths of metal within a coil - which is not always visible in the cold reduced product.

Coils

Steel sheet that has been wound. A slab, once rolled in a hot-strip mill, is more than one-quarter mile long; coils are the most efficient way to store and transport sheet steel.

Coining

A process of impressing images or characters of the die and punch onto a plane metal surface.

Coke (Tin) Plate

(Hot Dipped Tin Plate) Standard tin plate, with the lightest commercial tin coat, used for food containers, oil canning, etc. A higher grade is the best cokes, with special cokes representing the best of the coke tin variety. For high qualities and heavier coatings, see (Charcoal Tin Plate).

Coke

WHAT The basic fuel consumed in blast furnaces in the smelting of iron. Coke is a processed form of coal. About 1,000 pounds of coke are needed to process a ton of pig iron, an amount which represents more than 50% of an integrated steel mill's total energy use.
WHY Metallurgical coal burns sporadically and reduces into a sticky mass. Processed coke, However, burns steadily inside and out, and is not crushed by the weight of the iron ore in the blast furnace.
HOW Inside the narrow confines of the coke oven, coal is heated without oxygen for 18 hours to drive off gases and impurities.

Coke Oven Battery

A set of ovens that process coal into coke. Coke ovens are constructed in batteries of 10‹100 ovens that are 20 feet tall, 40 feet long, and less than two feet wide. Coke batteries, because of the exhaust fumes emitted when coke is pushed from the ovens, often are the dirtiest area of a steel mill complex.

Cold Reduced Strip

Metal strip, made from hot-rolled strip, by rolling on cold-reduction mills.

Cold Reduction

WHAT Finishing mills roll cold coils of pickled hot-rolled sheet to make the steel thinner, smoother, and stronger, by applying pressure, rather heat.
HOW Stands of rolls in a cold-reduction mill are set very close together and press a sheet of steel from one-quarter inch thick into less than an eighth of an inch, while more than doubling its length.

Cold Rolled Finish

Finish obtained by cold rolling plain pickled sheet or strip with a lubricant resulting in a relatively smooth appearance.

Cold Rolled Products

Flat rolled products for which the required final thickness has been obtained by rolling at room temperature.

Cold-Rolled Strip (Sheet)

Sheet steel that has been pickled and run through a cold-reduction mill. Strip has a final product width of approximately 12 inches, while sheet may be more than 80 inches wide. Cold-rolled sheet is considerably thinner and stronger than hot-rolled sheet, so it will sell for a premium (see Sheet Steel).

Cold Rolling

Rolling metal at a temperature below the softening point of the metal to create strain hardening (work-hardening). Same as cold reduction, except that the working method is limited to rolling. Cold rolling changes the mechanical properties of strip and produces certain useful combinations of hardness, strength, stiffness, ductility and other characteristics known as tempers.

Cold Short

The characteristics of metals that are brittle at ordinary or low temperatures.

Cold Shut

A defect produced during casting, causing an area in the metal where two portions of the metal in either a molten or plastic condition have come together but have failed to unite, fuse, or, blend into a solid mass. (See Lamination)

Cold Working (Rolling)

WHAT Changes in the structure and shape of steel achieved through rolling, hammering, or stretching the steel at a low temperature (often room temperature).
WHY To create a permanent increase in the hardness and strength of the steel.
HOW The application of forces to the steel causes changes in the composition that enhance certain properties. In order for these improvements to be sustained, the temperature must be below a certain range, because the structural changes are eliminated by higher temperatures.

Color Standard

A painted sheet panel with a prescribed color of paint representing the precise color it is intended to produce in the prepainted sheet. The color standard will preferably also be expressed in terms of physical attributes of hue, lightness and saturation called tristimulus values or derivatives of these values. A complete color standard definition will usually include painted panels representative of the limits of acceptable deviation from the precise standard color as well.

Columbium

(Chemical Symbol Cb) - Element No. 41 of the periodic system. Atomic weight 92.91. It is steel gray in color and brilliant luster. Specific gravity 8.57. Melting point at about 4379°F. It is used mainly in the production of stabilized austenitic chromium-nickel steels, also to reduce the air-hardening characteristics in plain chromium steels of the corrosion resistant type.

Commercial Bronze

A copper-zinc alloy (brass) containing 90% copper and 10% zinc; used for screws, wire, hardware, etc. Although termed “commercial-bronze” it contains no tin. It is someWhat stronger than copper and has equal or better ductility.

Commercial Finish

(See Finishes)

Commercial Quality Steel Sheet

Normally to a ladle analysis of carbon limited at 0.15 max. A Standard Quality Carbon Steel Sheet.

Commercial Steel (CS)

Sheet of this quality is for simple bending or moderate forming. Commercial Steel sheet can be bent flat upon itself in any direction at room temperature

Consumption

Measures the physical use of steel by end users. Steel consumption estimates, unlike steel demand figures, account for changes in inventories.
APPARENT SUPPLY. Derived demand for steel using AISI reported steel mill shipments plus Census Bureau reported imports, less Census Bureau reported exports. Domestic market share percentages are based on this figure, which does not take into account any changes in inventory.

Continuous Casting

WHAT A method of pouring steel directly from the furnace into a billet, bloom, or slab directly from its molten form.
WHY Continuous casting avoids the need for large, expensive mills for rolling ingots into slabs. Continuous cast slabs also solidify in a few minutes versus several hours for an ingot. Because of this, the chemical composition and mechanical properties are more uniform.
HOW Steel from the BOF or electric furnace is poured into a tundish (a shallow vessel that looks like a bathtub) atop the continuous caster. As steel carefully flows from the tundish down into the water-cooled copper mold of the caster, it solidifies into a ribbon of red-hot steel. At the bottom of the caster, torches cut the continuously flowing steel to form slabs or blooms.

Continuous Furnace

Furnace, in which the material being heated moves steadily through the furnace.

Continuous Picking

Passing sheet or strip metal continuously through a series of pickling and washing tanks.

Continuous Strip Mill

A series of synchronized rolling mill stands in which coiled flat rolled metal entering the first pass (or stand) moves in a straight line and is continuously reduced in thickness (not width) at each subsequent pass. The finished strip is recoiled upon leaving the final or finishing pass.

Controlled Atmosphere Furnaces

A furnace used for bright annealing into which specially prepared gases are introduced for the purposes of maintaining a neutral atmosphere so that no oxidizing reaction between metal and atmosphere takes place.

Controlled Rolling

A hot rolling process in which the temperature of the steel is closely controlled, particularly during the final rolling passes, to produce a fine-grain microstructure.

Conversion Coating

The chemical treatment film applied to the steel or metallic coated sheet prior to painting.

Conversion Cost

Resources spent to process material in a single stage, from one type to another. The costs of converting iron ore to hot metal or pickling hot-rolled coil can be isolated for analysis.

Converter

A furnace in which air is blown through the molten bath of crude metal or matte for the purpose of oxidizing impurities.

Converter/Processor

Demand from steel customers such as rerollers and tube makers, which process steel into a more finished state, such as pipe, tubing and cold-rolled strip, before selling it to end users. Such steel generally is not sold on contract, making the converter segment of the mills' revenues more price sensitive than their supply contracts to the auto manufacturers.

Cooling Stresses

Stresses develop by uneven contraction or external constraint of metal during cooling; also those stresses resulting from localized plastic deformation during cooling and retained.

Copper

(Chemical symbol Cu) - Element No. 29 of the periodic system, atomic weight 63.57. A characteristically reddish metal of bright luster, highly malleable and ductile and having high electrical and heat conductivity; melting point 1981°F.; boiling point 4237°F.; specific gravity 8.94. Universally used in the pure state as sheet, tube, rod and wire and also as alloyed by other elements (See Brass and Bronze), as an alloy with other metals.

Core Wound Flat Wire

(See Oscillated Wound Coils)

COREX®

WHAT COREX is a coal-based smelting process that yields hot metal or pig iron. Integrated mills or EAF mills can use the output.
HOW The process gasifies non-coking coal in a smelting reactor, which also produces liquid iron. The gasified coal is fed into a shaft furnace, where it removes oxygen from iron ore lumps, pellets or sinter; the reduced iron is then fed to the smelting reactor.

Corrosion

The gradual degradation or alteration of steel caused by atmosphere, moisture, or other agents.

If mild steel is exposed to an aerated neutral aqueous solution, for example a dilute solution of sodium chloride in water, then corrosive attack will begin at defects in the oxide film on the steel. These defects may be present as a result of mechanical damage such as scratches, or may be due to natural discontinuities in the film, i.e. inclusions, grain boundaries or dislocation networks at the surface of the steel.

At each defect the steel is exposed to the solution (electrolyte) and an anodic reaction occurs, resulting in the formation of iron ions and free electrons. These electrons are then conducted through the oxide film to take part in a cathodic reaction at the surface of the film. This reaction requires the presence of dissolved oxygen in the electrolyte and results in the formation of hydroxyl ions.

The hydroxyl ions react with the ferrous ions produced by the anodic reaction to form ferrous hydroxide, which is then converted into a hydrated oxide called, ?rust'. Gradually a scab of rust may form over the top of the pit, but this is too porous to completely block the anodic area. This allows the corrosion process to continue, resulting in deeper attack and widening of the anodic area as the surface oxide film breaks away.

If the pH of the solution in contact with the steel is low, for example a dilute acid, then the surface oxide film will be removed and the cathodic reaction will be different. Hydrogen gas will be liberated as gradual dissolution of the steel occurs. With oxidising acids, a number of alternate cathodic reactions may take place.

In all cases of corrosion the anodic reaction cannot proceed in isolation from the cathodic reaction and if either reaction can be limited or stopped then less or no corrosion will occur.

Corrosion Embrittlement

The embrittlement caused in certain alloys by exposure to a corrosive environment. Such material is usually susceptible to the intergranular type of corrosion attack.

Corrugated

As a defect. Alternate ridges and furrows. A series of deep short waves.

Creep

The flow or plastic deformation of metals held for long periods of time at stresses lower than the normal yield strength. The effect is particularly important if the temperature of stressing is above the recrystallization temperature of the metal.

Critical Cooling Rate

The minimum rate of continuous cooling just sufficient to prevent undesired transformations. For steel, the slowest rate at which it can be cooled form above the upper critical temperature to prevent the decomposition of austenite at any temperature above the Ms.

Critical Point

1) The temperature or pressure at which a change in crystal structure, phase or physical properties occurs; same as transformation temperature.
2) In an equilibrium diagram, that specific combination of composition, temperature and pressure at which the phases of an inhomogeneous system are in equilibrium.

Critical Rang

A temperature range in which an internal change takes place within a metal. Also termed Transformation Range.

Critical Surface

Intended for material applied to critical exposed/painted applications where cosmetic surface imperfections are objectionable. The prime side surface will be free of repetitive type imperfections, gouges, scratches, scale and slivers. This surface can only be furnished as a pickled product.

Crop

The defective ends of a rolled or forged product which are cut off and discarded.

Cross Break

(See Luders Lines) This term also applies to transverse ribs or ripples.

Cross Direction

(In rolled or drawn metal) The direction parallel to the axis of the rolls during rolling. The direction at, right angles to the direction of rolling or drawing.

Cross Rolling

Rolling at an angle to the long dimension of the metal; usually done to increase width.

Crown

A contour on a sheet where the thickness increases from some edge measurement to the center.

Crown or Heavy Center

Increased thickness in the center of metal sheet or strip as compared with thickness at the edge.

Crucible

A ceramic pot or receptacle made of graphite and clay, or other refractory materials, and used in the melting of metal. The term is sometimes applied to pots made of cast iron, cast steel or wrought steel.

Crucible Steel

High-carbon steel produced by melting blister steel in a covered crucible. Crucible steel was developed by Benjamin Huntsman in about 1750 and remained in use until the late 1940's.

Crystal

1) A physically homogeneous solid, in which the atoms , ions, or molecules are arranged in a three-dimensional repetitive pattern.
2) A coherent piece of matter, all parts of which have the same anisotropic arrangement of atoms; in metals, usually synonymous with “grain” and “crystallite.”

Crystalline

Composed of crystals.

Crystallization

The formation of crystals by the atoms assuming definite positions in a crystal lattice. This is What happens when a liquid metal solidifies. (Fatigue, the failure of metals under repeated stresses, is sometimes falsely attributed to crystallization.)

Cube-Centered

Metallography - (Concerning space lattices) - Body-centered cubic. Refers to crystal structure.

Cup Fracture

A type of fracture in a tensile test specimen which looks like a cup having the exterior portion extended with the interior slightly depressed.

Cut Edge

Removal of the as-rolled hot mill edge. Coil ends are cropped back to gauge when cut edge is ordered.

Cup Test

(See Olsen Ductility Test)

Culvert Pipe

Heavy gauge, galvanized steel that is spiral-formed or riveted into corrugated pipe, which is used for highway drainage applications.

Cut-to-Length

Process to uncoil sections of flat-rolled steel and cut them into a desired length. Product that is cut to length is normally shipped flat-stacked.

Cyaniding

Surface hardening of an iron-base alloy article or portion of it by heating at a suitable temperature in contact with a cyanide salt, followed by quenching.

Back to Top

Dead Flat

Perfectly flat. As pertaining to sheet, strip or plate. (See Stretcher Leveling)

Dead Soft Annealing

Heating metal to above the critical range and appropriately cooling to develop the greatest possible commercial softness or ductility.

Dead Soft Steel

Steel, normally made in the basic open-hearth furnace or by the basic oxygen process with carbon less than 0.10% and manganese in the 0.20-0.50% range, completely annealed.

Dead Soft Temper

(No. 5 TEMPER) - Condition of maximum softness commercially attainable in wire, strip, or sheet metal in the annealed state.

Deburring

A method whereby the raw slit edge of metal is removed by rolling or filing.

Decarburization

Removal of carbon from the outer surface of iron or steel, usually by heating in an oxidizing or reducing atmosphere. Water vapor, oxygen and carbon dioxide are strong decarburizers. Reheating with adhering scale is also strongly decarburizing in action.

Deep Drawing

The process of cold working or drawing sheet or strip metal blanks by means of dies on a press into shames which are usually more or less cup-like in character involving considerable plastic deformation of the metal. Deep-drawing quality sheet or strip steel, ordered or sold on the basis of suitability for deep-drawing.

Deep Drawing Steel (DDS)

Sheet of this designation should be used when Drawing Steel will not provide a sufficient degree of ductility for fabrication of parts having stringent drawing requirements, or applications that require the sheet be free from aging. This quality is made by special steelmaking and finishing practices.

Degassing Process

(In steel making) - Removing gases from the molten metal by means of a vacuum process in combination with mechanical action.

Delta Iron

Allotropic modification of iron, stable above 2552°F. to melting point. It is of body-centered cubic crystal structure.

Dent Resistant - BH Series

Sheet of this designation is produced from partially stabilized steel and offers a unique combination of as-received formability and final properties after fabrication. Sheet of this designation combines strength and high formability. Although this steel is non-aging at room temperature, it gains strength from work-hardening during fabrication and from carbon-aging during paint-baking. (Sometimes referred to as "bake hardenable.")

Deoxidizing

Removal of oxygen. In steel sheet, strip, and wire technology, the term refers to heat treatment in a reducing atmosphere, to lessen the amount of scale. (See Controlled Atmosphere Furnaces)

Die-Lines

Lines of markings caused on drawn or extruded products by minor imperfections in the surface of the die.

Die Sinking

Forming or machining a depressed pattern in a die.

Dish

A concave surface departing from a straight line edge to edge. Indicates transverse or across the width.

Desulfurization

WHAT Operation that injects a chemical mixture into a ladle full of hot metal to remove sulfur prior to its charging into the Basic Oxygen Furnace.
WHY Sulfur enters the steel from the coke in the blast furnace smelting operation, and there is little the steelmaker can do to reduce its presence. Because excess sulfur in the steel impedes its welding and forming characteristics, the mill must add this step to the steelmaking process.

Direct Reduced Iron (DRI)

WHAT Processed iron ore that is iron-rich enough to be used as a scrap substitute in electric furnace steelmaking.
WHY As mini-mills expand their product abilities to sheet steel, they require much higher grades of scrap to approach integrated mill quality. Enabling the mini-mills to use iron ore without the blast furnace, DRI can serve as a low residual raw material and alleviate the mini-mills' dependence on cleaner, higher-priced scrap.
HOW The impurities in the crushed iron ore are driven off through the use of massive amounts of natural gas. While the result is 97% pure iron (compared with blast furnace hot metal, which, because it is saturated with carbon, is only 93% iron), DRI is only economically feasible in regions where natural gas is attractively priced.

Doctor Blade Steel Strip

A hardened and tempered spring steel strip, usually blued, produced from approximately .85 carbon cold rolled spring steel strip specially selected for straightness and good edges. Sometimes hand straightened or straightened by grinding and cut to desired lengths. This product is used in the printing trade as a blade to uniformly remove excess ink (“dope”) from the rolls; hence its name.

Drawing

(See Tempering)

Drawing Steel (DS)

Sheet of this quality has a greater degree of ductility and is more consistent in performance than Commercial Steel because of higher standards in production, selection and melting of the steel

Drawing Back

Reheated after hardening to a temperature below the critical for the purpose of changing the hardness of the steel. (See Tempering)

Drawn-Over-Mandrel

A procedure for producing specialty tubing using a drawbench to pull tubing through a die and over a mandrel, giving excellent control over the inside diameter and wall thickness. Advantages of this technique are its inside and outside surface quality and gauge tolerance. Major markets include automotive applications and hydraulic cylinders.

Drill Pipe

Pipe used in the drilling of an oil or gas well. Drill pipe is the conduit between the wellhead motor and the drill bit. Drilling mud is pumped down the center of the pipe during drilling, to lubricate the drill bit and transmit the drilled core to the surface. Because of the high stress, torque and temperature associated with well drilling, drill pipe is a seamless product.

Drill Rod

A term given to an annealed and polished high carbon tool steel rod usually round and centerless ground. The sizes range in round stock from .013 to 1 ½” diameter. Commercial qualities embrace water and oil hardening grades. A less popular but nevertheless standard grade is a non-deforming quality. Drill Rods are used principally by machinists and tool and die makers for punches, drills, taps, dowel pins, screw machine parts, small tools, etc.

Dry Film Thickness (DFT)

The thickness of the dry paint film.

Dry Rolled Finish

Finish obtained by cold rolling on polished rolls without the use of any coolant or metal lubricant, material previously plain pickled, giving a burnished appearance.

DS Type B Steel

Product intended for applications that require particularly severe drawing and forming.

Ductility

Ability of steel to undergo permanent changes in shape without fracture at room temperature.

Dumping

Dumping occurs when imported merchandise is sold in, or for export to, the domestic market at less than the normal value of the merchandise, i.e., a price which is less than the price at which identical or similar merchandise is sold in the comparison market, the home market (market of exporting country) or third-country market (market used as proxy for home market in cases where home market cannot be used). The normal value of the merchandise cannot be below the cost of production.

Dumping Margin

The amount by which the normal value exceeds the export price or constructed export price of the subject merchandise.

Duplex

A category of stainless steel with high amounts of chromium and moderate nickel content. The duplex class is so named because it is a mixture of austenitic (chromium-nickel stainless class) and ferritic (plain chromium stainless category) structures. This combination was originated to offer more strength than either of those stainless steels. Duplex stainless steels provide high resistance to stress corrosion cracking (formation of cracks caused by a combination of corrosion and stress) and are suitable for heat exchangers, desalination plants, and marine applications.

Duralumin

The trade name applied to the first aluminum-copper-magnesium type of age-hardenable alloy (17S), which contains nominally 4% Cu, ½ % Mg. The term is sometimes used to include the class of wrought aluminum-copper-magnesium alloys that harden during aging at room temperature.

Back to Top

Earing

Wavy projections formed at the opera end of a cup or shell in the course of deep drawing because of differences in directional properties. Also termed scallop. (See Non-Scalloping Quality Strip Steel)

Edges

Many types of edges can be produced in the manufacture of flat rolled metal products. Over the years the following types of edges have become recognized as standard in their respective fields.
COPPER BASE ALLOYS: Slit, Slit and Edge Rolled, Sheared, Sawed, Machined or Drawn,
SHEET STEELS OR ALUMINUM SHEET: Mill Edge, Slit Edge or Sheared Edge.
STRIP STEELS and STAINLESS STRIP:
No.1 Edge - A smooth, uniform, round or square edge, either slit or filed or slit and edge rolled as specified, width tolerance +/-.005”.
No.2 Edge - A natural round mill edge carried through from the hot rolled band. Has not been slit, filed, or edge rolled. Tolerances not closer than hot-rolled strip limits.
No.3 Edge - Square, produced by slitting only. Not filed. Width tolerance close.
No.4 Edge - A round edge produced by edge rolling either from a natural mill edge or from slit edge strip. Not as perfect as No. 1 edge. Width tolerances liberal.
No.5 Edge - An approximately square edge produced by slitting and filing or slitting and rolling to remove burr.
No.6 Edge - A square edge produced by square edge rolling, generally from square edge hot-rolled occasionally from slit strip. Width tolerances and finish not as exacting as No. 1 edge.

Edge Filing

A method whereby the raw or slit edges of strip metal are passed or drawn one or more times against a series of files, mounted at various angles. This method may be used for deburring only or filing to a specific contour including a completely rounded edge.

Edge Rolling (Edge Conditioning)

Rolling a strip of steel to smooth the edges. By removing the burr off the coil, it is safer for customers to manipulate.

Edge Strain or Edge Breaks

Creases extending in from the edge of the temper rolled sheet.

Edgewise Curvature

(See Camber)

Edging

The dressing of metal strip edges by rolling, filing or drawing.

Elastic Limit

Maximum stress that a material will stand before permanent deformation occurs.

Electric Arc Furnace (EAF)

Steelmaking furnace where scrap is generally 100% of the charge. Heat is supplied from electricity that arcs from the graphite electrodes to the metal bath. Furnaces may be either an alternating current (AC) or direct current (DC). DC units consume less energy and fewer electrodes, but they are more expensive.

Electric Furnance Steel

Steel made in any furnace where heat is generated electrically, almost always by arc. Because of relatively high cost, only tool steels and other high-value steels are made by the electric furnace process.

Electric Resistance Welded (ERW) Pipe

Pipe made from strips of hot-rolled steel which are passed through forming rolls and welded. While seamless pipe is traditionally stronger and more expensive than comparable ERW pipe, ERW technology is improving and the technique now accounts for approximately 48% of OCTG shipments by tonnage.

Electrical Steel

(See Silicon Electrical Steel)

Electrocleaning

(Electrolytic Brightening) - An anodic treatment. A cleaning, polishing, or oxidizing treatment in which the specimen or work is made the anode in a suitable electrolyte; an inert metal is used as cathode and a potential is applied.

Electro-Galvanizing

Galvanizing by electrodeposition of zinc on steel.

Electrolytic Polishing

(See Electrocleaning)

Electrolytic Tin Plate

Black Plate that has been tin plated on both sides with commercially pure tin by electrodeposition. (See Tin Plating)

Electroplating

The production of a thin coating of one metal on another by electrodeposition. It is very extensively used in industry and is continuing to enlarge its useful functions. Various plated metals and combinations thereof are being used for different purpose to illustrate:

1. Decoration and protection against corrosioncopper, nickel & chromium
2. Protection against corrosioncadmium or zinc
3. Protection against wearchromium
4. Build-up of a part or parts undersizechromium or nickel
5. Plate for rubber adhesionbrass
6. Protection agnst carburization & for brazing operationscopper & nickel

Elongation

Increase in length which occurs before a metal is fractured, when subjected to stress. This is usually expressed as a percentage of the original length and is a measure of the ductility of the metal.

Embossed sheet

An embossed sheet is one having a prominent, impressed texture or pattern on its surface(s). If the defined texture is applied to essentially on surface only, it is most properly termed a coined surface. If the texture or pattern carries through the entire body of the sheet and appears on both surfaces it is a true embossed surface.

Embossing

Raising or indenting a design in relief on a sheet or strip of metal by passing between rolls of desired pattern. (See Patterned or Embossed Sheet)

Endurance Limit

Maximum alternating stress, which a given material will withstand for an indefinite number of times, without causing fatigue failure.

Erichsen Test

Similar to the Olsen Test. Readings are in millimeters.

Etching

In metallography, the process of revealing structural details by the preferential attack of reagents on a metal surface.

Eutectoid Steel

Steel representing the eutectoid composition of the iron carbon system, with about 0.80% to 0.83% carbon, the eutectoid temperature being about 1333°F. Such steel in the annealed condition consists exclusively of pearlite. Steels with less than this quota of carbon are known as hypo-eutectoid and contain free ferrite in addition to the pearlite. When more carbon is present, the steel is known as hyper-eutectoid and contains free cementite. The presence of certain elements, such as nickel or chromium, lowers the eutectoid carbon content.

Extensometer

An apparatus for indicating the deformation of metal while it is subjected to stress.

Extensometer Test

The measurement of deformation during stressing in the elastic range, permitting determination of elastic properties such as proportional limit, proof stress, yield strength by the offset method and so forth. Requires the use of special testing equipment and testing procedures such as the use of an extensometer or the plotting of a stress-strain diagram.

Extra Deep Drawing Steel

Sheet of this designation has superior formability and excellent uniformity. It is produced from steel having a very low carbon content with stabilizing elements added to make it interstitial free. It is a non-aging steel sheet with high resistance to thinning during drawing and is suitable for critical forming applications.

Extra Hard Temper

In brass mill terminology, Extra Hard is six B & S numbers hard or 50.15% reduction from the previous annealing or soft stage.

Extra Spring Temper

In brass mill terminology, Extra Spring is ten numbers hard or 68.55% reduction in thickness from the previous annealing or soft stage.

Extra Smooth Galvanized

An Extra-Smooth finish is imparted to hot-dip metallic-coated steel sheet by temper rolling after coating to decrease the surface relief that occurs when the molten coating solidifies. The spangle pattern (grain pattern) is made distinctly less visible by the matte finish imparted by the rolling operation. Most Extra-Smooth sheet is intended for either prepainted or post painted applications.

Extrusion

Shaping metal into a chosen continuous form by forcing it through a die of appropriate shape.

Back to Top

Fabricator

A producer of intermediate products that does not also produce primary metal. For example, a rebar (see Reinforcing Bar) fabricator purchases rebar and processes the material to the specifications of a particular construction project.

Fastmet

A process to directly reduce iron ore to metallic iron pellets that can be fed into an electric arc furnace with an equal amount of scrap. This process is designed to bypass the coke oven-blast furnace route to produce hot metal from iron ore. It is also one of several methods that mini-mills might use to reduce their dependence on high-quality scrap inputs (see Direct Reduced Iron and Hot Briquetted Iron).

Ferritic

The second-largest class of stainless steel, constituting approximately 25% of stainless production. Ferritic stainless steels are plain chromium steels with no significant nickel content; the lack of nickel results in lower corrosion resistance than the austenitics (chromium-nickel stainless steels). Ferritics are best suited for general and high-temperature corrosion applications rather than services requiring high strength. They are used in automotive trim and exhaust systems, interior architectural trim, and hot water tanks. Two of the most common grades are type 430 (general-purpose grade for many applications, including decorative ones) and type 409 (low-cost grade well suited to withstanding high temperatures).

Ferroalloy

A metal product commonly used as a raw material feed in steelmaking, usually containing iron and other metals, to aid various stages of the steelmaking process such as deoxidation, desulfurization, and adding strength. Examples: ferrochrome, ferromanganese, and ferrosilicon.

Ferrochrome

An alloy of iron and chromium with up to 72% chromium. Ferrochrome is commonly used as a raw material in the making of stainless steel.

Ferrous

Metals that consist primarily of iron.

Finish

The surface appearance of steel after final treatment.

Finish Coat

The topcoat or exposed prime side paint film.

Finishing Facilities

The portion of the steelmaking complex that processes semi-finished steel (slabs or billets) into forms that can be used by others. Finishing operations can include rolling mills, pickle lines, tandem mills, annealing facilities, and temper mills.

Finmet

The process reduces iron ore fines with gas in a descending series of fluidized bed reactors. The reduced iron is hot briquetted.

Flat-Rolled Steel

Category of steel that includes Sheet, Strip, and Tin Plate, among others.

Flatness

Flatness is a measure of a cut length sheet's ability to conform to a flat horizontal surface. Maximum deviation from that surface is the degree to which the sheet is out of flat. Flatness is often expressed quantitatively in either Steepness or I-Units

Flexibility

The degree to which a paint film can withstand deformation without significant change in color and appearance

Flux

An iron-cleaning agent. Limestone and lime react with impurities within the metallic pool to form a slag that floats to the top of the relatively heavier (and now more pure) liquid iron.

FOB Pricing

See FREIGHT ON BOARD PRICING

FREIGHT ON BOARD PRICING

Phrase that explains whether the transportation costs of the steel are included. "FOB Mill" is the price of steel at the mill, not including shipping.

FREIGHT EQUALIZATION

A common industry practice when a mill sells steel outside its geographic area; it will assume any extra shipping costs (relative to the competition) to quote the customer an equivalent price to get the business.

Back to Top

Galvalume®

Steel sheet with a unique coating of 55% aluminium and 45% zinc that resists corrosion. The coating is applied in a continuous hot-dipped process, which improves the steel's weather resistance. Galbanum® is a trademark of BHP Steel, and the product is popular in the metal building market.

Galvanized Steel

Steel coated with a thin layer of zinc to provide corrosion resistance in underbody auto parts, garbage cans, storage tanks, or fencing wire. Sheet steel normally must be cold-rolled prior to the galvanizing stage.
HOT-DIPPED. Steel is run through a molten zinc coating bath, followed by an air stream "wipe" that controls the thickness of the zinc finish.
ELECTROGALVANIZED. Zinc plating process whereby the molecules on the positively charged zinc anode attach to the negatively charged sheet steel. The thickness of the zinc coating is readily controlled. By increasing the electric charge or slowing the speed of the steel through the plating area, the coating will thicken.
DIFFERENCES. Electrogalvanizing equipment is more expensive to build and to operate than hot dipped, but it gives the steelmaker more precise control over the weight of the zinc coating. The automotive manufacturers, because they need the superior welding, forming and painting ability of electrogalvanized steel, purchase 90% of all tonnage produced.

Galvanizing

Coating steel with zinc and tin (principally zinc) for rust proofing purposes. Formerly for the purpose of galvanizing, cut length steel sheets were passed singly through a bath of the molten metal. Today's galvanizing processing method consists of uncoiling and passing the continuous length of successive coils either through a molten bath of the metal termed Hot Dipped Galvanizing or by continuously zinc coating the uncoiled sheet electrolytically- termed Electro-Galvanizing.

Gamma Iron

The form of iron stable between 1670 (degrees) F., and 2550 (degrees) F., and characterized by a face-centered cubic crysta structure.

Gauge

The thickness of sheet steel. Better-quality steel has a consistent gauge to prevent weak spots or deformation.

Gloss

The property of a surface related to its ability to reflect light. The most common type of gloss of interest to appearance attributes is specular gloss. The parameters which must be specified for the determination of this property are the angles of incidence of the light source, the angle of viewing of the gloss and the angular dispersions of the measuring beams.

Gray Cast Iron

A cast iron that gives a gray fracture due to the presence of flake graphite. Often called gray iron.

Greenfield Steel Mill

New mill that is built "from scratch," presumably on a green field.

Ground Flat Stock

Annealed and pre-ground (to close tolerances) tool steel flats in standard sizes ready for tool room use. These are three common grades; water hardening, oil hardening, and air hardening quality.

Back to Top

Half Hard Temper

(A) No. 2 Temper. In low carbon cold-rolled strip steel, produced by cold rolling to a hardness next to but someWhat softer than full hard temper.
(B) In brass Stainless Steel Strip, tempers are based on minimum tensile or yield strength. For Chromium-Nickel grades Half-Hard Temper 150,000 TS., 110,000 YS. Min.

Hard Drawing

Drawing metal wire through a die to reduce cross section and increase tensile strength.

Hard Drawn

Wire or tubing drawn to high tensile strength by a high degree of cold work.

Hard Drawn Spring Steel Wire

A medium high carbon cold drawn spring steel wire. Used principally for cold springs.

Hardenability

The ability of a metal, usually steel, to harden in depth as distinguished from the terms “hardness.”

Hardened & Tempered Spring Steel Srip

A medium or high carbon quality steel strip which has been subjected to the sequence of heating, quenching and tempering.

Hardness

Degree to which a metal will resist cutting, abrasion, penetration, bending and stretching. The indicated hardness of metals will differ someWhat with the specific apparatus measuring hardness. (See Brinell Hardness, Rockwell Hardness, Vickers Hardness, Scleroscope Hardness) Tensile Strength also is an indication of hardness.

Hard Temper

(A) For Steel see Full Hard Temper.
(B) In brass mill terminology. Hard Temper is four B & S numbers hard or 37.1 % reduction.

Hardening

WHAT Process that increases the hardness of steel, i.e., the degree to which steel will resist cutting, abrasion, penetration, bending, and stretching.
WHY The increased endurance provided by hardening makes steel suitable for additional applications.
HOW Hardening can be achieved through various methods, including (1) heat treatment, where the properties of steel are altered by subjecting the steel to a series of temperature changes; and (2) cold working, in which changes in the structure and shape of steel are achieved through rolling, hammering, or stretching the steel at a relatively low temperature.

Heat (of steel)

A batch of refined steel. A basic oxygen or electric furnace full of steel. One heat of steel will be used to cast several slabs, blooms or billets.

Heat Treatment

WHAT Altering the properties of steel by subjecting it to a series of temperature changes.
WHY To increase the hardness, strength, or ductility of steel so that it is suitable for additional applications.
HOW The steel is heated and then cooled as necessary to provide changes in the structural form that will impart the desired characteristics. The time spent at each temperature and the rates of cooling have significant impact on the effect of the treatment.

Heavy Structural Shapes

A general term given to rolled flanged sections that have at least one dimension of their cross sections three inches or greater. The category includes beams, channels, tees and zees if the depth dimension is three inches or greater, and angles if the length of the leg is three inches or greater.

High Brass

65% - A copper-zinc alloy containing 35% zinc. Possesses high tensile strength and is used for springs, screws, rivets, etc.

High-Carbon Steel

Steel with more than 0.3% carbon. The more carbon that is dissolved in the iron, the less formable and the tougher the steel becomes. High-carbon steel's hardness makes it suitable for plow blades, shovels, bedsprings, cutting edges, or other high-wear applications.

High Strength

Product intended for applications where greater strength is critical. High Strength typically begins at 35 ksi minimum yield strength.

High Strength Low Alloy (HSLA)

A specific group of steels in which the strength levels are achieved by the addition of moderate amounts of alloying elements. The most common are columbium, vanadium or titanium.

Hooke’s Law

Stress is proportional to strain in the elastic range. The value of the stress at which a material ceases to obey Hooke’s law is known as the elastic limit.

Hot Band (Hot-Rolled Steel)

A coil of steel rolled on a hot-strip mill (hot-rolled steel). It can be sold in this form to customers or further processed into other finished products.

Hot Briquetted Iron (HBI)

Direct reduced iron that has been processed into briquettes. Instead of using a blast furnace, the oxygen is removed from the ore using natural gas and results in a substance that is 90%-92% iron. Because DRI may spontaneously combust during transportation, HBI is preferred when the metallic material must be stored or moved.

Hot Dip

In steel mill practice, a process whereby ferrous alloy base metals are dipped into molten metal, usually zinc, tin or terne, for the purpose of fixing a rust resistant coating.

Hot End

The section of a steelmaking complex from the furnace up to, but not including, the hot-strip mill.

Hot Metal

The name for the molten iron produced in a blast furnace. It proceeds to the basic oxygen furnace in molten form or is cast as pig iron.

Hot Rolled Sheet

Steel sheet that is processed to its final thickness by rolling at high temperatures on a specially designed hot-rolling facility. Also commonly known as hot rolled unprocessed.

Hot Rolled Sheet Non-Temper Rolled

A U. S. Steel definition for product supplied as a coil directly off the Hot Strip Mill with no additional processing.

Hot Rolled Sheet Pickled

A U. S. Steel definition for a mill edge coil that is pickled, oiled and temper rolled with coil ends cropped back to meet gauge tolerances.

Hot Rolled Sheet Pickled Non-Temper Rolled

A U. S. Steel definition for a mill edge coil that is pickled and oiled with coil ends cropped back to meet gauge tolerances.

Hot Rolled Sheet Products

Flat steel products that are brought to final thickness by rolling through a Hot Strip Mill at high temperatures.

Hot Short

Brittleness in hot metal.

Hot-Strip Mill

A rolling mill of several stands of rolls that converts slabs into hot-rolled coils. The hot-strip mill squeezes slabs, which can range in thickness from 2-10 inches, depending on the type of continuous caster, between horizontal rolls with a progressively smaller space between them (while vertical rolls govern the width) to produce a coil of flat-rolled steel about a quarter-inch in thickness and a quarter mile in length.

Hot Top

(See Sinkhead)

Hot Working

Plastic deformation of metal at a temperature sufficiently high not to create strain hardening. The lower limit of temperature for this process is the recrystallization temperature.

Hydroforming

A forming process in which a tube is placed into a forming die. The tube is then formed to the shape of the die through the application of internal water pressure. The hydroforming process allows for severe shape deformation, making it ideal for automotive structural parts such as engine cradles, radiator supports and body rails. Various shaped and sized holes can be punched in the tube almost anywhere during the process.

Hydrogen Embrittlement

1) Brittleness of metal, resulting from the occlusion of hydrogen (usually as a by-product of pickling or by co-deposition in electroplating).
2) A condition of low ductility resulting from hydrogen absorption and internal pressure developed subsequently. Electrolytic copper exhibits similar results when exposed to reducing atmosphere at elevated temperature.

Hypereutectoid Steel

A steel having more than the eutectoid percentage of carbon. (See Eutectoid Steel)

Hupoeutectoid Steel

Steel with less than eutectoid percentage of carbon. (See Eutectoid Steel)

HYL I, HYL III

Processes for producing DRI and HBI developed by Hylsa. The processes reduce iron ore lump or pellets with reformed natural gas in a vertical shaft furnace. The HYL I process uses four fixed-bed reactors; HYL III uses a single-shaft furnace.

Back to Top

I-Beams

Structural sections on which the flanges are tapered and are typically not as long as the flanges on wide-flange beams. The flanges are thicker at the cross sections and thinner at the toes of the flanges. They are produced with depths of 3-24 inches.

Immersed Scanning

In ultrasonics, a planned, systematic movement of the beam relative to the object being inspected, the search unit being coupled to this object through a column of liquid. In most cases the object and the search unit are submerged in water.

Impact Test

Test designed to determine the resistance of metal to breakage by impact, usually by concentrating the applied stress to a notched specimen.

Impurities

Elements or compounds whose presence in a material is undesired.

Inclusion

A nonmetallic material in a solid metallic martial

Inclusion Shape Control

The use of rare earth metals or calcium alloys to control the morphology of inclusions, in order to provide improved mechanical properties for select applications.

Indentation Hardness

The resistance of a meterial to indentation. This is the usual type osf hardness test, in which a pointed or rounded indenter is pressed into a surface under a substantially static load.

Induction Hardening

Quench hardening in which the heat is generated by electrical induction.

Induction Hardening

A process of hardening a ferrous alloy by heating it above the transformation range by means of electrical induction, and then cooling as required.

Induction Heating

A process of heating by electrical induction.

Intercoat Adhesion

The adherence which is observed between the primer and topcoat of a paint system.

Inert-Gas Shielded-Arc Welding

Arc welding in an inert gas such as argon or helium.

Ingot

A form of semi-finished steel. Liquid steel is teemed (poured) into molds, where it slowly solidifies. Once the steel is solid, the mold is stripped, and the 25- to 30-ton ingots are then ready for subsequent rolling or forging.

Ingot Iron

Commercially pure open-hearth iron.

Inhibitor

A substance which retards some specific chemical reaction. Pickling inhibitors retard the sissolution of metal without hindering the removal of scale from steel.

Inmetco

WHAT Inmetco is a coal-based process similar to FASTMET that uses iron oxide fines and pulverized coal to produce a scrap substitute. Mill scale and flue dust, inexpensive byproducts of steelmaking, can be mixed with the iron oxide fines. Inmetco, unlike other direct reduction products, is intended to be hot charged into an EAF, with attendant energy savings.
HOW The process includes three steps. First, iron oxide fines, pulverized coal and a binder are formed into pellets. Second, the pellets, two to three layers deep, are heated in a gas-fired rotary hearth furnace for 15-20 minutes to produce sponge iron. Subsequently, the iron must be desulfurized. The coal in the pellets provides much of the energy required in the second phase.

Integrated Mills

These facilities make steel by processing iron ore and other raw materials in blast furnaces. Technically, only the hot end differentiates integrated mills from mini-mills. However, the differing technological approaches to molten steel imply different scale efficiencies and, therefore, separate management styles, labor relations and product markets. Nearly all domestic integrated mills specialize in flat-rolled steel or plate.

Interleaving

The placing of a sheet of paper between two adjacent layers of metal to facilitate handling and shearing of rectangular sheets, or to prevent sticking or scratching.

Intermediate Annealing

An annealing treatment given to wrought metals following cold work hardening for the purpose of softness prior to further cold working. (See Process Annealing)

Interrupted Aging

The aging of an alloy at two or more temperatures by steps, and cooling to room temperatures after each step. Compare with Progressive Aging.

Interstitial Free Steel

A recently developed sheet steel product with very low carbon levels that is used primarily in automotive deep-drawing applications. Interstitial Free Steel's improved ductility (drawing ability) is made possible by vacuum degassing.

Investment Casting

1) Casting metal into a mold produced by surrounding (investing) an expendable pattern with a refractory slurry that sets at room temperature after which the wax, plastic, or frozed mercury pattern is removed through the use of heat. Also called precision casting, or lost-wax process.
2) A casting made by the process.

Iron

(Chemical symbol Fe.) Element No. 26 of the periodic system; Atomic weight 55.85. A magnetic silver white metal of high tensile strength, ductile and malleable. Melting point of pure iron about 2795 (degrees) F. Chemically iron is chiefly base forming. The principal forms of commercial iron are steel, cast iron and wrought iron.

Iron Carbide

One of several substitutes for high-quality, low-residual scrap for use in electric furnace steelmaking. Iron carbide producers use natural gas to reduce iron ore to iron carbide.

Iron Ore

Mineral containing enough iron to be a commercially viable source of the element for use in steelmaking. Except for fragments of meteorites found on Earth, iron is not a free element; instead, it is trapped in the earth's crust in its oxidized form.

Ironing

Thinning the walls of deep drawn articles by reducing the clearance between punch and die.

Isothermal Annealing

A process on which a ferrous alloy is heated to produce a structure partly or wholly austenitic, and is then cooled to and held at a temperature that causes transformation of the austenite to a relatively soft ferrite-carbide aggregate

Back to Top

Jig Saw Steel

Hardened, tempered and bright polished with round edges. Carbon content .85. Ranges of sizes .039 to 393 in width and .016 to .039 in thickness.

Back to Top

Killed Steel

Steel deoxidized with a strong deoxidizing agent, such as silicon or aluminium, to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification.

Killed Steel

The term killed indicates that the steel has been sufficiently deoxidized to quiet the molten metal when poured into the ingot mold. The general practice is to use aluminum ferrosilicon or manganese as deoxidizing agents. A properly killed steel is more uniform as to analysis and is comparatively free from aging. However, for the same carbon and manganese content Killed Steel is harder than Rimmed Steel. In general all steels above 0.25% carbon are killed, also all forging grades, structural steels from 0.15% to 0.25% carbon and some special steels in the low carbon range. Most steels below 0.15% carbon are rimmed steel.

Kind Band (deformation)

In polycrystalline materials, a volume of crystal that has rotated physically to accommodate differential deformation between adjoining parts of a grain while the band itself has deformed homogeneously. This occurs by regular bending of the slip lamellae along the boundaries of the band.

Back to Top

Ladle Analysis

A term applied to the chemical analysis representative of a heat of steel as reported by the producer. It is determined by analyzing a test ingot sample obtained during the pouring of the steel from a ladle.

Ladle Metallurgy Furnace (LMF)

An intermediate steel processing unit that further refines the chemistry and temperature of molten steel while it is still in the ladle. The ladle metallurgy step comes after the steel is melted and refined in the electric arc or basic oxygen furnace, but before the steel is sent to the continuous caster.

Lamination

An abnormal structure resulting in a separation or weakness aligned generally parallel to the worked surface of the metal.

Lap

A surface defect, appearing as a seam, caused by fording over hot metal, fins, or sharp corners and then rolling or forging them into the surface, but not welding them.

Lap-Weld

A term applied to a weld formed by lapping two pieces of metal and then pressing or hammering, and applied particularly to the longitudinal joint produced by a welding process for tubes or pipe, in which the edges of the skelp are beveled or scarfed so that when they are overlapped they can be welded together.

Lath Martensite

Martensite formed, partly in steel containing less than about 1.0% C and solely in steels containing less than about 0.5% C, as parallel arrays or packets of lath-shape units about 0.1 to 0.3 m thick, and having a habit plane that is close to {111}.

Lattice

Space lattice. Lattice lines and lattice planes are lines and planes chosen so as to pass through collinear lattice points, and non-collinear lattice points, respectively.

Lead Annealing

(See Bath Annealing)

Leveling

Flattening rolled metal sheet or strip. (See Roller and Stretcher Leveling)

Leveling Line

A process to flatten any shape deficiencies (wavy edges and buckles) in the sheet, prior to final shipment. Most cold-rolled sheet initially has a crowned cross-section that, if such a shape is undesirable to the customer, must be flattened in the leveling line.

Life Cycle Costing

An accounting method of costing where expenses are allocated over the life of the product. Life cycle costs are often lower for stainless steel than for alternatives despite a higher initial outlay, because stainless products generally last longer and require little maintenance.

Light Metals

Metal and alloys that have a low specific gravity, such as beryllium, magnesium and aluminum.

Light-Gauge Steel

Very thin steel sheet that has been temper-rolled or passed through a cold-reduction mill. Light gauge steel normally is plated with tin or chrome for use in food containers.

Line Pipe

Pipe used in the surface transmission of oil, natural gas and other fluids.

Liquation

Partial melting of an alloy.

Liquidus

In a constitutional diagram, the locus of points representing the temperatures at which various components commence freezing on cooling or finish melting on heating.

Lithographic Sheet Aluminum

Sheet having a superior surface on one side with respect to freedom from surface imperfections and supplied with a maximum degree of flatness, for use as a plate in offset printing.

Long Products

Classification of steel products that includes bar, rod and structural products, that are "long", rather than "flat".

Long Terne

A term applying to steel sheets that have been terne coated (Lead and Tin) by immersion in a bath of Terne Metal.

Longitudinal Direction

The principal direction of flow in a worked metal.

Low Brass

80% cu. A copper-Zinc alloy containing 20% zinc. Is a light golden color, very ductile, suitable for cupping, drawing, forming, etc. Because of its good strength and corrosion resistance it is used for flexible metal gose, metal bellows, etc.

Low-Carbon Steel

Steel with less than 0.005% carbon is more ductile (malleable): It is capable of being drawn out or rolled thin for use in automotive body applications. Carbon is removed from the steel bath through vacuum degassing.

Low Carbon Steels

Contain from 0.10 to 0.30% carbon and less than 0.60% manganese. (The product of Basic Oxygen, Bessemer, Open Hearth or Electric Processes.)

Low-Hydrogen Electrode

A covered arc-welding electrode that provides an atmosphere around the arc and molten weld metal which is low in hydrogen.

Luders Lines (Steel)

(Characteristic of No. 5 Yemper-Not a defect in No. 5 dead soft temper.) Long vein-like marks appearing on the surface of certain metals, in the direction of the maximum shear stress, when the metal is subjected to deformation beyond the field point.

Luders Lines or Bands

Elongated surface markings or depressions caused by localized plastic deformation that results form discontinuous (inhomogeneous) yielding.

Luster Finish

Refer to Finish.

Back to Top

M B Grade

A term applied to Open-Hearth steel wire in the .45/.75 carbon range either hard drawn or oil tempered. Oil tempered wire of M B and W M B types are the most widely used of all spring wires. Oil tempered wire is more suitable to precision forming and casting operations than hard drawn wire, because of close control of tensile strength and superior straightness. . NOTE M B, H B and extra H B designate Basic Open Hearth steels, while W M B, W H B and extra W H B designate Acid Open Hearth Steels. The chemical composition and the mechanical properties are the same for both basic and acid steel.

M sections (Bantam BeamsTM , Junior BeamsTM)

Light footweight beams primarily used in the construction of pre-engineered housing. These beams are produced in lighter footweights, usually six to 10 pounds per foot, than traditional structural products.

Machinability

The relative ease of machining a metal.

Machinability Index

A relative measure of the machinability of an engineering material under specified standard conditions.

Macroetch Test

Consists of immersing a carefully prepared section of the steel in hot acid and of examining the etched surface to evaluate the soundness and homogeneity of the product being tested.

Macrograph

A photographic reproduction of any object that has not been magnified more than ten times.

Macroscopic

Visible either with the naked eye or under low magnification (as great as about ten diameters).

Macrostructure

The structure of metal as revealed by macroscopic examination.

Magnetic-Particle Inspection

A nondestructive method of inspection for determining the existence and extent of possible defects in ferromagnetic materials. Finely divided magnetic particles, applied to the magnetized part, are attracted to and outline the pattern of any magnetic-leakage fields created by discontinuities.

Magnetite

The oxide or iron of intermediate valence, which has a composition close to the stoichiometric composition Fe3O4.

Malleability

The property that determines the ease of deforming a metal when the metal is subjected to rolling or hammering. The more malleable metals can be hammered or rolled into thin sheet more easily than others.

Malleabilizing

A process of annealing white cast iron in such a way that the combined carbon is wholly or partly transformed to graphitic or free carbon or, in someinstances, part of the carbon is removed completely.

Manganese

(Chemical symbol Mn.) Element No. 25 of the periodic system; atomic weight 54.93. Lustrous, reddish-white metal of hard brittle and, therfore, non-malleable character. The metal is used in large quantities in the form of Spiegel and Ferromanganese for steel manufacture as well as in manganese and many copper-base alloys. Its principal function is as an alloy in steel making: (1) It is ferrite-strengthening and carbide forming element. It increases hardenability inexpensively, with a tendency toward embrittlement when too high carbon and too high manganese accompany each other. (2) It counteracts brittleness from sulfur.

Magnesium

(Chemical symbol Mg.) - Element No. 12 of the periodic system; atomic weight 24.305. Specific gravity 1.77 with a melting point of approximately 1160°F. A silver-white light malleable, ductile metallic element that occurs abundantly in nature. The metal is used in metallurgical and chemical processes; in photography, in signaling, and in the manufacture of pyrotechnics because of the intense white light it produces on burning.

Man-Hours Per Ton

This is a measure of labor efficiency the ratio of total hours worked by steel employees to the tons shipped for a given period of time. Changes in the inventory level and work that is contracted out will affect the reported measurement.

Manual Welding

Welding where in the entire welding operation is performed and controlled by hand.

Martempering

Quenching an austenitized ferrous alloy in a medium at a temperature in the upper part of the martensite range, or slightly above that range, and holding it in the medium until the temperature throughout the alloy is substantially uniform. The alloy is then allowed to cool in air through the martensite range.

Martempering

1) A hardening procedure in which an austenitized ferrous material is quenched into an appropriate medium at a temperature just above the Ms temperature of the material, held in the medium until the temperature is uniform through-out -but not long enough for bainite to form - and then cooled in air. The treatment is frequently followed by tempering.
2) When the process is applied to carburized material, the controlling Ms temperature is that of the case. This variation of the process is frequently called marquenching.

Martensite

In steel, a metalstable transition phase with a body-centered-tetragonal crystal structure formed by diffusionless transformation of austenite generally during cooling between the Ms and Mf temperatures.

Martensite

A distinctive neddle like structure existing in steel as a transition stage in the transformation of austenite. It is the hardest constituent of steel of eutectoid composition. It is produced by rapid cooling from quenching temperature and is the chief constituent of hardened carbon tool steels. Martensite is magnetic.

Martensite Range

The interval between the Ms and Mf temperatures.

Martensitic Stainless Steel

Has a body centered tetragonal (BCT) structure. These alloys are chromium stainless steels with medium to high carbon levels. They work harden slowly in the annealed (soft) condition but can be heat-treated to very high tensile strengths.

Martensitic

Small category of stainless steel characterized by the use of heat treatment for hardening and strengthening. Martensitic stainless steels are plain chromium steels with no significant nickel content. They are utilized in equipment for the chemical and oil industries and in surgical instruments. The most popular martensitic stainless steel is type 410 (a grade appropriate for non-severe corrosion environments requiring high strength).

Matalloid

(a) Element intermediate in lustre and conductivity between the true metals and non-metals. Arsenic, antimony, boron, tellurium, and selenium, etc., are generally considered metalloids; frequently one allotropic modification of an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn.
(b) In steel metallurgy, metalloid has a specialized, even if erroneous, meaning; it covers elements commonly prosent in simple steel; carbon, manganese, phosphorus, silicon and sulfur.

Matrix

The principal phase or aggregate in which another constituent is embedded.

Matt or Matte Finish

(Steel) Not as smooth as normal mill finish. Produce by etched or mechanically roughened finishing rolls.

Mechanical Properties

The properties of a material that reveal its elastic and inelastic behavior where force is applied, thereby indicating its suitability for mechanical application; for example, modulus of elasticity, tensile strength, elongation, hardness, and fatigue limit.

Mechanical Properties

Those properties of a meterial that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength and fatigue limit. These properties have often been designated as physical properties, but the term mechanical properties is much to be preferred. The mechanical properties of steel are dependent on its microstructure.

Mechanical Spring

Any spring produced by cold forming from any material with or without subsequent heat treatment.

Mechanical Twin

A twin formed in a metal during plastic deformation by simple shear of the structure.

Mechanical Working

Plastic deformation or other physical change to which metal is subjected, by rolling, hammering, drawing., etc. to change its shape, properties or structure.

Medium-Carbon Steel

Contains from 0.30% to 0.60% carbon and less than 1.00% manganese. May be made by any of the standard processes.

Metalloid

(a) Element intermediate in luster and conductivity between the true metals and non-metals. Arsenic, antimony, boron, tellurium, and selenium, etc., are generally considered metalloids; frequently one allotropic modification of an element will be non-metallic, another metalloid in character. Obviously, no hard and fast line can be drawn.
(b) In steel metallurgy, metalloid in has a specialized, even of erroneous, meaning; is covers elements commonly present in simple steel; carbon, manganese, phosphorus, silicon and sulfur.

Melting Point

The temperature at which a pure metal, compound or eutectic changes form solid to liquid; the temperature at which the liquid and the solid are in equilibrium.

Melting Range

The range of temperature in which an alloy melt; that is the range between solidus and liquidus temperatures.

Merchant Bar

A group of commodity steel shapes that consist of rounds, squares, flats, strips, angles, and channels, which fabricators, steel service centers and manufacturers cut, bend and shape into products. Merchant products require more specialized processing than reinforcing bar.

Metal

An opaque, lustrous, elemental substance that is a good conductor of heat and electricity and, when polished, a good reflector or light. Most metals are malleable and ductile and are, in general, denser than other substances.

Metal Spraying

A process for applying a coating of metal to an object. The metal, usually in the form of wire, is melted by an oxyhydrogen or oxyacetylene blast or by an electric arc and is proficted at high speed by gas pressure against the object being coated.

Metallography

The science concerning the constituents and structure of metals and alloys as revealed by the microscope.

Metalograph

An optical instrument designed for both visual observation and photomicrography of prepared surfaces of opaque materials at magnifications ranging from about 25 to about 1500 diameters.

Metastable

Possessing a state of pseudo-equilibrium that has a free energy higher than that of the true equilibrium state but from which a system does not change spontaneously.

Mf Temperature

The temperature at which martensitic transformation is essentially complete during cooling after austenitization.

Mil

A term used to indicate the thickness of the paint film. A dry film thickness of 0.001", i.e., the standard dry film thickness after curing for several common paints, is one (1) mil.

Microbands (deformation)

Thin sheet like volumes of constant thickness in which cooperative slip occurs on a fone scale. They are an instability which carry exclusively the deformation at medium strains when normal homogeneous slip is precluded. The sheets are aligned at +/- 55(degrees) to the compression direction and are confined to individual grains, which usually contain two sets of bands. Compare shear bands.

Microcrack

A crack of microscopic size.

Micrograph

A graphic reproduction of the prepared surface of a specimen at a magnification greater than ten diameters. When photographed, the reproduction is known as a photomicrograph (not a microphotograph).

Microstructure

The structure of a prepared surface of a metal as revealed by a microscope at a magnification greater than ten diameters.

Microstructure

The structure of polished and etched metal and alloy specimens as revealed by the microscope.

Mild Steel

Carbon steel containing a maximum of about 0.25% C.

Mill Edge

The edge of strip, sheet or plate in the as rolled state. Unsheared.

Mill Finish

A surface finish produced on sheet and plate. Characteristic of the ground finish used on the rolls in fabrication.

Mini-Mills

Normally defined as steel mills that melt scrap metal to produce commodity products. Although the mini-mills are subject to the same steel processing requirements after the caster as the integrated steel companies, they differ greatly in regard to their minimum efficient size, labor relations, product markets, and management style.

Modulus of Elasticity

A measure of the rigidity of metal. Ratio of stress, within proportional limit, to corresponding strain. Specifically, the modulus obtained in tension or compression is Young's modulus, stretch modulus or modulus of extensibility; the modulus obtained in torsion or shear is modulus of rigidity, shear modulus or modulus of torsion; the modulus covering the ratio of the mean normal stress to the change in volume per unit volume is the bulk modulus. The tangent modulus and secant modulus are not restricted within the proportional limit; the former is the slope of the stress-strain curve at a specified point; the latter is the slope of a line from the origin to a specified point on the stress-strain curve. Also called elastic modulus and coefficient of elasticity.

Modulus of Elasticity (tension)

Force which would be required to stretch a substance to double its normal length, on the assumption that it would remain perfectly elastic, i.e., obey Hooke's Law throughout the twist. The ratio of stress to strain within the perfectly elastic range.

Modulus of Rigidity

Of a material suffering shear, the ratio of the intensity of the shear stress across the section to the shear strain, i.e., to the angle of distortion in radians; expressed on pounds or tons per square inch.

Mold

A form of cavity into which molten metal is poured to produce a desired shape.

Molybdenum

(Chemical symbol Mo) Element No. 42 of the peridic system; atomic weight 95.95. Hard, tough metal of grayish-white color, becoming very ductile and malleable when properly treated at high temperatures; melting point 4748 (degrees) F.; boiling point about 6600 (degrees) F.; specific gravity 10.2 . Pure molybdenum can best be obtained as a black powder, by reduction of molybdenum trioxide or ammonium molybdate with hydrogen. From this powder, ductile sheet and wire are made by powder metallurgy techniques; these are used in radio and related work. Its principal functions as an alloy in steel making: (1) Raises grain-coarsening temperature of austenite. (2) Deepens hardening. (3) Counteracts tendency toward temperbrittleness. (4) Raises hot and creep strength, red hardness. (5) Enhances corrosion resistance in stainless steel. (6) Forms abrasion-resisting particles.

Molybdenum (Mo)

An alloying element used as a raw material for some classes of stainless steel. Molybdenum in the presence of chromium enhances the corrosion resistance of stainless steel.

Months of Inventory

Ratio of the end-of-period inventory to average monthly level of sales for the period.

Ms Temperature

The temperature at which a martensitic transformation starts during cooling after austenitization.

Muntz Metal (A refractory Alloy)

Alpha-beta brass, 60% copper and 40% zinc. Stronger than alpha-brass and used for castings and hot-worked (rolled, stamped, or extruded) products. High strength brasses are developed from this by adding other elements.

Music Wire

A polished high tensile strength cold drawn wire with higher tensile strength and higher torsional strength than any other material available. The high toughness characteristic of this material is obtained by the patenting. Such wire is purchased according to tensile strength, not hardness.

Back to Top

Natural Aging

Spontaneous aging of a supersaturated solid solution at room temperature.

Needle Cutter Steel

Usually supplied quarter hard rolled, extra precision rolled with sheared edges. Carbon content 1.25 - Chromium .15. Usually supplied in a 2 width from .002 to .035. Used for cutting the eyes of needle and milling the latch in a latch needle.

Network Structure

A structure in which the crystals of one constituent are surrounded by envelopes of another constituent which gives a network appearance to an etched test specimen.

Nickel (Ni)

An alloying element used as a raw material for certain classes of stainless steel. Nickel provides high degrees of ductility (ability to change shape without fracture) as well as resistance to corrosion. Approximately 65% of all nickel is used in the making of stainless steel.

Nickel

(Chemical symbol Ni) Element No. 28 of the periodic system; atomic weight 58.69. Silvery white, slightly magnetic metal, of medium hardness and high degree of ductility and malleability and resistance to chemical and atmospheric corrosion; melting point 2651 (degrees) F.; boiling point about 5250 (degrees) F., specific gravity 8.90. Used for electroplating. Used as an alloying agent, it is of great importance in iron-base alloys in stainless steels and in copper-base alloys such as Cupro-Nickel, as well as in nickel-base alloys such as Monel Metal. Its principal functions as an alloy in steel making: (1) Strengthens unquenched or annealed steels. (2) Toughens pearlitic-ferritic steels (especially at low temperature). (3) Renders high-chromium iron alloys austenitic.

Nickel Silver

Copper base alloys that contain 10-45% Zn. and 5-30% Ni.

Nickel Steel

Steel containing nickel as an alloying element. Varying amounts are added to increase the strength in the normalized condition to enable hardening to be performed in oil or air instead of water.

Niobium

(Chemical symbol Nb) Element No. 41 of the periodic system.

Nitriding

Introducing nitrogen into a solid ferrous alloy by holding at a suitable temperature (below Ac1 for ferritic steels) in contact with a nitrogenous material, usually ammonia of molten cyanide of appropriate composition. Quenching is not required to produce a hard case.

Nitriding

Process of surface hardening certain types of steel by heating in ammonia gas at about 935-1000 (degrees) F., the increase in hardness being the result of surface nitride formation. Certain alloying constituents, principal among them being aluminum, greatly facilitate the hardening reaction. In general, the depth of the case is less than with carburizing.

Nitriding Steel

Steel which is particularly suited for the nitriding process, that is, it will form a very hard and adherent surface upon proper nitriding (heating in a partially dissociated atmosphere of ammonia gas). Composition usually .20-.40 carbon, .90-1.50 chromium, .15-1.00 molybdenum, and .85-1.20% aluminum.

No. 1 Heavy Melt

Obsolete steel scrap grade, at least one-quarter inch in thickness and in sections no larger than five feet by two feet. Much of the metal comes from demolished buildings, truck frames and heavy duty springs. Mini-mills are primary consumers of No. 1 heavy scrap.

Non-Ferrous Metals

Metals or alloys that are free of iron or comparatively

Non-Metalic Inclusions

Impurities (commonly oxides), sulphides, silicates or similar substances held in metals mechanically during solidification or formed by reactions in the solid state.

Non-Refractory Alloy

A term opposed to refractory alloy. A non-refractory alloy has malleability, that is, ease of flattening when subjected to rolling or hammering.

Non-Scalloping Quality Strip Steel

Strip steel ordered or sold on the basis of absence of unevenness, or ears, on the edges of the steel, when subjected to deep drawing.

Normalizing

A heat treatment applied to steel, Involves heating above the critical range followed by cooling in still air. Is performed to refine the crystal structure and eliminate internal stress.

Notch Brittleness

A measure of the susceptibility of a material to brittle fracture at locations of stress concentration. For example, in a notch tensile test a material is said to be notch brittle if its notch strength is less than its tensile strength; otherwise, it is said to be notch ductile.

Number as Pertaining to Edge

(See Edges)

Number as Pertaining to Hardness

In copper base alloys industry; temper is referred to as so many numbers hard, i.e.; Yellow Brass Half Hard is termed 2 numbers hard. This term is derived from terminology used on the mill floor whereby temper or hardness is imparted by cold working and classified as to hardness by the number of Brown & Sharpe gages away from the soft or as-annealed state.

Number as Pertaining to Temper

(See Temper)

Back to Top

OCTG

includes casing, drill pipe and oil well tubing, which, depending on their use, may be formed through welded or seamless processes.

Oil

Applied after pickling or temper rolling to assist customer handling by minimizing inter-wrap gouging, improve lubricity and provide a more rust resistant product.

Oil Country Tubular Goods (OCTG)

Label applied to the pipe products used by petroleum exploration customers.

Oil Hardening

A process of hardening a ferrous alloy of suitable composition by heating within or above the transformation range and quenching in oil.

Oil-Hardening Steel

Steel adaptable to hardening by heat treatment and quenching in oil.

Oiled Sheet

Sheet product that is processed with the final step being the application of oil to the surface. Usually, the oil is intended to provide protection from rusting during shipment and storage. These oils are called rust-preventative oils. The oil may also serve to assist in the subsequent fabrication process, but this is not usually the main purpose. Oils used to enhance formability are often called prelubricants or "prelubes".

Oil Stain Aluminum

Stain produced by the incomplete burning of the lubricants on the surface of the sheet. Rolling subsequent to staining will change color from darker browns to lighter browns down to white.

Olsen (DUCTILITY) Test

A method of measuring the ductility and drawing properties of strip or sheet metal which involves determination of the width and depth of impression. The test simulating a deep drawing operation is made by a standard steel ball under pressure, continuing until the cup formed from the metal sample fractures. Readings are in thousandths of an inch. This test is sometimes used to detect stretcher straining and indicates the surface finish after drawing, similar to the Erichsen ductility test.

Open Hearth Furnace

A broad, shallow hearth to refine pig iron and scrap into steel. Heat is supplied from a large, luminous flame over the surface, and the refining takes seven to nine hours. Open Hearths, at one time the most abundant steelmaking furnaces among integrated companies, have been replaced by the basic oxygen furnace.

Open-Hearth Process

Process of making steel by heating the metal in the hearth of a regenerative furnace. In the basic open-hearth steel process, the lining of the hearth is basic, usually magnesite; whereas in the acid open-hearth steel process, an acid material, silica, is used as the furnace lining and pig iron, extremely low in phosphorous (less than 0.04%), is the raw material charged in.

Open Surface

Rough surface on black plate, sheet or strip, resulting from imperfection in the original steel bars from which the plate was rolled.

Orange Peel

(Effect) - A surface roughening (defect) encountered in forming products from metal stock that has a coarse grain size. It is due to uneven flow or to the appearance of the overly large grains usually the result of annealing at too high a temperature. Also referred to as “pebbles” and “alligator skin.”

Order Rate

The ratio of new orders recorded to the mill's capacity to produce the steel to fill the orders. Many analysts view trends in the order rate as harbingers of future production levels.

Ore

A mineral from which metal is (or may be) extracted.

Orientation

(Crystal) - Arrangement of certain crystal axes or crystal planes in a polycrystalline aggregate with respect to a given direction or plane. If there is any tendency for one arrangement to predominate, it is known as the preferred orientation. In the absence of any such preference, random orientation exists.

Oscillated Wound or Scroll Wound

A method of even winding metal strip or wire on to a reel or mandrel wherein the strands are uniformly overlapped. Sometimes termed “stagger wound” or “vibrated wound.” The opposite of ribbon wound.

Oscillating

A method of winding narrow strip steel over a much wider roll. Customers want to have as much steel on a coil as will fit in their machines, so they can spend less time moving the material and more time using it. By coiling the strip like fishing line (or thread) over a spool, a much longer strip can fit onto a coil of proper diameter. Oscillate-wound coils allow the customer to enjoy longer processing runs.

Overaging

Aging under conditions of time and temperature greater than those required to obtain maximum change in a certain property, so that the property is altered in the direction of the initial value.

Overheating

Heating a metal or alloy to such a high temperature that its properties are impaired. When the original properties cannot be restored by further heat treating, by mechanical working, or by combination of working and heat treating, the overheating is known as burning.

Oxidation

The addition of oxygen to a compound. Exposure to atmosphere sometimes results in oxidation of the exposed surface, hence a staining or discoloration. This effect is increased with temperature increase.

Oxidation

1) A reaction in which there is an increase in valence resulting from a loss of electrons.
2) Chemical combination with oxygen to form an oxide.

Oxide

Compound of oxygen with another element.

Oxygen Lance

A length of pipe used to convey oxygen onto a bath of molten metal.

Back to Top

Pack Rolling

Rolling two or more pieces of thin sheet at the same time, a method usually practiced in rolling sheet into thin foil.

Pass

A term indicating the process of passing metal through a rolling mill.

Patent Leveling

(See Stretcher Leveling)

Patenting

A heat treatment applied to medium and high-carbon steel prior to cold drawing to wire. The treatment involves austenitization followed by isothermal transformation at a temperature that produces a microstructure of very fine pearlite.

Patenting

Treatment of steel, usually in wire form, in which the metal is gradually heated to about 1830 (degrees) F., with subsequent colling, usually in air, in a bath of molten lead, or in a fused salt mixture held between 800 (degrees) F. and 1050 (degrees) F.

Pattern Welding

A process in which strips or other small sections of iron or steel are twisted together and then forge welded. Homogeneity and toughness are thereby improved. A regular decorative pattern can be developed in the final product. Commonly used for making swords as early as the 3rd century A.D.

Patterned or Embossed Sheet

A sheet product on which a raised or indented pattern has been impressed on either on or both surfaces by the use of rolls.

Peak Earnings

The ultimate earnings level of a company at the top of the business cycle. This is the expected profit during the time of the highest commodity demand and the strongest product pricing.

Pearlite

A eutectoid transformation product of ferrite and cementite that ideally has a lamellar structure but that is always degenerate to some extent.

Pearlite

Lamellar structure resembling mother of pearl. A compound of iron and carbon occurring in steel as a result of the transformation of austenite into aggregations of ferrite and iron carbide.

Pellets

(See Agglomerating Processes)

Pencil Hardness

A physical measurement of the hardness of a paint film which is based on the resistance of the film to cut-through by pencil leads of specified hardness. Pencil hardness values range between 2B and 5H.

Penetrant Inspection

A method of non-destructive testing for determining the existence and extent of discontinuities that are open to the surface in the part being inspected. The indications ore made visible through the use of a dye or fluorescent chemical in the liquid employed as the inspection medium.

Peritectic

An isothermal reversible reaction in which a liquid phase reacts with a solid phase to produce another solid phase.

Permalloy

Nickel alloys containing about 20 to 60% Fe, used for their high magnetic permeability and electrical resistivity.

Permanent Set

Non-elastic or plastic, deformation of metal under stress, after passing the elastic limit.

Phase Diagram

Synonymous with constitutional diagram.

Phosphor Bronze

Copper base alloys, with 3.5 to 10% of tin, to which has been added in the molten state phosphorous in varying amounts of less than 1% for deoxidizing and strengthening purposes. Because of excellent toughness, strength, fine grain, resistance to fatigue and wear, and chemical resistance, these alloys find general use as springs and in making fittings. It has corrosion resisting properties comparable to copper.

Phosphor Bronze Strip

A copper-based alloy containing up to 10% tin, which has been deoxidized with phosphorous in varying amounts of less than 1 % (see Phosphor Bronze). Temper is imparted by cold rolling, resulting in greater tensile strength and hardness than in most copper-base alloys or either of its alloying elements copper or tin. The various tempers from “One Number Hard” to “Ten Numbers Hard” are classified in hardness by the number of B & S Gages reduction in dimension from the previous soft or as annealed state (See Brown & Sharpe Gages). Phosphor Bronze is not heat treatable for purposes of hardness development. It does not withstand elevated temperatures very well and should not be used in service above 225°F. even after stress relieving treatment at 325 to 350°F. It has excellent electrical properties, corrosion resistant comparable to copper; great toughness and resistance to fatigue. Rated good for soft soldering, silver alloy brazing, oxyacetylene, carbon arc and resistance welding.

Phosphorus

(Chemical symbol P) - Element No. 15 of the periodic system; atomic weight 30.98. Non-metallic element occurring in at least three allotropic forms; melting point 111°F.; boiling point 536°F.; specific gravity 1.82. In steels it is usually undesirable with limits set in most specifications. However, it is specified as an alloy in steel to prevent the sticking of light-gage sheets; to a degree it strengthens low carbon steel; increases resistance to corrosion, and improves machinability in free-cutting steels. In the manufacture of Phosphor Bronze it is used as a deoxidizing agent.

Photomicrograph

A photographic reproduction of any object magnified more than ten diameters. The term micrograph may be used.

Physical Properties

Those properties familiarly discussed in physics, exclusive of those described under mechanical properties; for example, density, electrical conductivity, co-efficient of thermal expansion. This term often has been used to describe mechanical properties, but this usage is not recommended. (See Mechanical Properties)

Pickling

WHAT Process that cleans a steel coil of its rust, dirt and oil so that further work can be done to the metal.
WHY When hot-rolled coils cool, rust forms on the unprotected metal; often coils are stored or transported while exposed to outside air and water.
HOW Through a continuous process, the steel is uncoiled and sent through a series of hydrochloric acid baths that remove the oxides (rust). The steel sheet is then rinsed and dried.

Pickling Patch

A defect in tin plate, galvanized or terne plated steel due to faulty pickling, leaving areas from which the oxide has not been completely removed.

Pig Iron

The name for the melted iron produced in a blast furnace, containing a large quantity of carbon (above 1.5%). Named long ago when molten iron was poured through a trench in the ground to flow into shallow earthen holes, the arrangement looked like newborn pigs suckling. The central channel became known as the "sow," and the molds were "pigs."

Piling (Sheet Piling)

A structural steel product with edges designed to interlock; used in the construction of cofferdams or riverbank reinforcement.

Pin Expansion Test

A test for determining the ability of tubes to be expanded or for revealing the presence of cracks or other longitudinal weaknesses, made by forcing a tapered pin into the open end of a tube.

Pinch Pass Temper

(See Soft Skin Rolled Temper and/or Temper Rolling)

Pinchers

Long fern like creases usually diagonal to the direction of rolling.

Pinholes

Microscopic imperfection of the coatings, that is, microscopic bare spots, also microscopic holes penetrating through a layer or thickness of light gage metal.

Pipe

Technically a tube used to transport fluids or gases. However, pipe and tube are often used interchangeably in steel lexicon, with a given label applied primarily as a matter of historical use.

Pit

(Defect) - A sharp depression in the surface of the metal.

Pitting

Forming small sharp cavities in a metal surface by nonuniform electro-deposition or by corrosion.

Planimetric Method

A method of measuring grain size, in which the grains within a definite area are counted.

Planishing

Producing a smooth surface finish on metal by rapid succession of blows delivered by highly polished dies or by a hammer designed for the purpose, or by rolling in a planishing mill.

Plastic Deformation

Deformation that remains, or will remain, permanent after release of the stress that caused it.

Plasticity

The ability of a metal to be deformed extensively without rupture.

Plate

Sheet steel with a width of more than eight inches, with a thickness ranging from one quarter of an inch to more than one foot (see Sheet Steel).

Plate Martensite

Martensite formed, partly in steels containing more than about 0.5% C and solely in steels containing more than about 1.0% C, as lenticular-shape plates on irrational habit planes that are near (225)A, or {259}A in very-high-carbon steels

Plating

A thin coating of metal laid on another metal.

PM 2.5

The moniker for the Environmental Protection Agency's new Particulate Matter standards. The EPA is revising current PM standards and establishing a new PM 2.5 standard regarding the release of particulate matter down to 2.5 micrometers in diameter (less than one-third the width of a human hair).

Polished Surface

The finish obtained by buffing with rouge or similar fine abrasive, resulting in a high gloss or polish.

Polishing

Producing a specularly reflecting surface.

Polycrystalline

Comprising an aggregate of more than one crystal, and usually a large number of crystals.

Polymorphism

The ability of a material to exist in more than one crystallographic structure. Numerous metals change in crystallographic structure at transformation temperatures during heating or cooling. If the change is reversible, it is allotropy. The allotropy of iron, particularly the changes between the alpha body-centered and the gamma face centered form, is of fundamental importance in the hardening of steel.

Polymorphism

The property whereby certain substances may exist in more than one crystalline form, the particular form depending on the conditions of crystallization - e.g., temperature and pressure. Among elements, this phenomenon is also called allotropy.

Postheating

Heating weldments immediately after welding, for tempering, for stress relieving, or for providing a controlled rate of cooling to prevent formation of a hard or brittle structure.

Pot

A vessel for holding molten metal. Also used to refer to the electrolytic reduction cell employed in winning certain metals, such as aluminum, from a fused electrolyte.

Pot Annealing

Is the same as Box Annealing.

Pouring

The transfer of molten metal from the ladle into ingot molds or other types of molds; for example, in castings.

Powder Metallurgy

The art of producing metal powders and of utilizing metal powders for the production of massive materials and shaped objects.

Powder Metals

Fabrication technology in which fine metallic powder is compacted under high pressure and then heated at a temperature slightly below the melting point to solidify the material. Primary users of powder metal parts are auto, electronics and aerospace industries.

Precipitation Hardening

Hardening caused by the precipitation of a constituent form a supersaturated solid solution.

Precipitation Hardening (PH)

A small group of stainless steels with high chromium and nickel content, with the most common types having characteristics close to those of martensitic (plain chromium stainless class with exceptional strength) steels. Heat treatment provides this class with its very high strength and hardness. Applications for PH stainless steels include shafts for pumps and valves as well as aircraft parts.

Precipitation Heat Treatment

Nonfer met. Any of the various aging treatments conducted at elevated temperatures to improve certain of the mechanical properties through precipitation from solid solution.

Preheating

Heating before some further thermal or mechanical treatment. For tool steel, heating to an intermediate temperature immediately before austenitizing. For some nonferrous alloys, heating to a high temperature for a long time, in order to homogenize the structure before working.

Preheating

1) A general term used to describe heating applied as a preliminary to some further thermal or mechanical treatment.
2) A term applied specifically to tool steel to describe a process in which the steel is heated slowly and uniformly to a temperature below the hardening temperature and is then transferred to a furnace in which the temperature is substantially above the preheating temperature. (3) Nonfer. met.-Heating a metal to a relatively high temperature for a relatively long time in order to change the structure before working. Ingots are homogenized by preheating.

Pressure Vessel Steel (PVS)

Product intended for pressure vessels and similar end use applications

Prelubricant

An oil coating that is applied to steel sheet to enhance formability (deep drawing). This lubricant is usually applied when the customer wishes to avoid the application of a forming lubricant in his plant.

Primes

Metal products, such as sheet and plate, of the highest quality and free from visible surface defects.

Primer Coat

The base coat of paint in a typical two-coat system. Primer coats are usually applied to produce a dry film thickness of approximately 0.2 mil.

Process Annealing

In the sheet and wire industries, a process by which a ferrous alloy is heated to a temperature close to, but below, the lower limit of the transformation range and is subsequently cooled. This process is applied in order to soften the alloy for further cold working.

Proeutectoid (phase)

Particles of a phase that precipitate during cooling after austenitizing but before the eutectoid transformation takes place.

Progressive Aging

An aging process in which the temperature of the alloy is continually increased during the aging cycle. The temperature may be increased in steps or by any other progressive method.

Proportional Limit

The greatest stress that the material is capable of sustaining without a deviation from the law of proportionality of stress to strain. (Hooke’s Law)

Puddling Process

A process for making wrought iron in which cast orn is melted in a hearth furnace and rabbled with slag and oxide until a pasty mass is obtained. This process was developed by Henry Cort about 1784 and remained in use until 1957, although on a very small scale during the present century.

Pulse-Echo Method

A nondestructive test in which pulses of energy are directed onto a part, and the time for the echo to return from one or more reflecting surfaces is measured.

Pulverized Coal Injection System (PCI)

A blast furnace enhancement to reduce an integrated mill's reliance on coke (because of environmental problems with its production). Up to 30% of the coke charged into the blast furnace can be replaced by this talcum-like coal powder, which is injected through nozzles at the bottom of the furnace.

Punch

The movable part that forces the metal into the die in equipment for sheet drawing, blanking, coining, embossing and the like.

Punching

Shearing holes in sheet metal with punch and die.

Pyrometer

An instrument of various types used for measuring temperatures.

Back to Top

Q-BOP

Modified Basic Oxygen Furnace in which the oxygen and other gases are blown in from the bottom, rather than from the top. While the Q-BOP stirs the metal bath more vigorously, allowing for faster processing, the design produces essentially the same steel grades as the top-blowing basic oxygen furnace. Today's state-of-the-art furnace design combines the previous technologies: 60% of the oxygen is blown from above, with the rest blown through the bottom of the vessel.

Qualification Trials

The testing required for a new process adopted to make certain grades of steel with exacting end uses. In order for the process to become qualified, the steel made by the process must be tested.

Quality

A term used to denote the degree of perfection of the steel sheet. Often, for sheet products, relative quality refers to the degree of perfection of the surface, i.e., the lack of scratches, absence of slivers, etc. Quality can also refer to other attributes such as internal soundness, dimensional control, etc.

Quarter Hard (No. 3 Temper)

(A) In low carbon cold-rolled strip steel, a medium soft temper produced by a limited amount of cold rolling after annealing.
(B) In brass mill terminology. Quarter hard is one B and S number hard or 10.95% reduction. (C) In stainless steel terminology tempers are based on minimum tensile, or yield strength. For Chromium-Nickel grades Quarter Hard Temper is 125,000 T. S., 75,000 Y.S. min.

Quench Aging

Aging that occurs after quenching following solution heat treatment.

Quench Hardening

Hardening a ferrous alloy by austenitizing and then cooling rapidly enough so that some or all of the austenite transforms to martensite. The austenitizing temperature for hypoeutectoid steels is usually above Ac3 and for hypereutectoid steels usually between Ac1 and Ac (cm).

Quench Hardening (Steel)

A process of hardening a ferrous alloy of suitable composition by heating within or above the transformation range and cooling at a rate sufficient to increase the hardness substantially. The process usually involves the formation of martensite.

Quenching

Rapid cooling.

Quenching

In the heat treating of metals, the step of cooling metals rapidly in order to obtain desired properties; most commonly accomplished by immersing the metal in oil or water. In the case of most copper base alloys, quenching has no effect other than to hasten cooling.

Back to Top

Radiant Tube Annealing Box

A box which is heated, inside, by means of tubes on which gas is burned; the hot tubes radiate their heat to the covered pile of metal, standing on the base of the box. Usually a protective atmosphere is maintained in the box to protect the metal from oxidation. - (See Annealing)

Radiography

A nondestructive method of internal examination in which metal objects are exposed to a beam of X-ray or gamma radiation. Differences in thickness, density or absorption, caused by internal defects or inclusions, are apparent in the shadow image either on a fluorescent screen or on photographic film placed behind the object.

Ragged Edges

Edges of Sheet or Strip which are torn, split, cracked, ragged or burred or otherwise disfigured.

Recarburizing

1) Increasing the carbon content of molten cast iron or steel by adding carbonaceous material, high-carbon pig iron or a high-carbon alloy.
2) Carburizing a metal part to return surface carbon lost in processing.

Reciprocal Lattice (for a crystal)

A group of points arranged about a center in such a way that the line joining each point of the center is perpendicular to a family of planes in the crystal, and the length of this line is inversely proportional to their interplanar distance.

Recovery

1) The removal of residual stresses by localized plastic flow as the result of low-temperature annealing operations; performed on cold worked metals without altering the grain structure or strength properties substantially.

Recrystallization

1) The change from one crystal structure to another, as occurs on heating or cooling through a critical temperature.
2) The formation of a new, strain-free grain structure from that existing in cold worked metal, usually accomplished by heating.

Recrystallization Temperature

The approximate minimum temperature at which complete recrystallization of a cold worked metal occurs within a specified time.

Recystallization Annealing

Annealing cold worked metal to produce a new grain structure without a phase change.

Red Brass

85% Copper -- A copper-zinc alloy containing approximately 15% zinc, used for plumbing pipe, hardware, condenser tubes. Because of its color, is used or vanity cases, coins, plaques, badges, etc. It is someWhat stronger than commercial bronze and is hardened more rapidly by cold working.

Red Shortness

Brittleness in steel when it is red hot.

Reducing Agent

Either natural gas or coal can be used to remove the oxygen from iron ore in order to produce a scrap substitute. In gas-based processes, the iron ore is heated in a vessel as reformed natural gas passes through. In coal-based processes, iron ore is combined with gasified or ground coal and heated. The oxygen in the ore combines with carbon and hydrogen in the gas or coal, producing reduced, or metallic, iron.

Reduction of Area

1) Commonly, the difference, expressed as a percentage of original area, between the original cross-sectional area of a tensile test specimen and the minimum cross-sectional area measured after complete separation.
2) The difference, expressed as a percentage of original area, between original cross-sectional area and that after straining the specimen.

Refining Temperature

A temperature, usually just higher than the transformation range, employed in the heat treatment of steel to refine the structure -- in particular, the grain size.

Reflector Sheet

An alclad product containing on one side a surface layer of high-purity aluminum superimposed on a core or base alloy of commercial-purity aluminum or an aluminum-manganese alloy. The high-purity coating imparts good polishing characteristics and the core gives adequate strength and formability.

Reflectivity (Reflectance)

A term to indicate the percentage of reflected light from a painted surface. Considered a function of color rather than specular gloss. Reflectance percentages usually range from 80% to 90% for white colors to 5% to 15% for dark colors. Reflectivity standards vary for each industry and specific application.

Refractory

A heat-resistant material, usually nonmetallic, which is used for furnace linings and such.

Refractory Alloy

A term applied to those alloys which due to hardness or abrasiveness present relative difficulty in maintaining close dimensional tolerances.

Refractory Brick

Heat-resistant brick. Because its melting point is well above the operating temperatures of the process, refractory bricks line most steelmaking vessels that come in contact with molten metal, like the walls of the blast furnace, sides of the ladles, and inside of the BOF.

Registry Printing

Printing successive colors or figures in a precise pattern and with exact superposition.

Reinforcing Bar (Rebar)

A commodity-grade steel used to strengthen concrete in highway and building construction.

Reline

The process of replacing the refractory lining of a liquid steel vessel. Once it wears out, the brick lining of a furnace must be cooled, stripped and replaced. This maintenance can be significant because a blast furnace reline may require up to three months to complete.

Rephosphorizing (Steel)

A Ladle-chemical treatment consisting of the addition of phosphorus as a work hardening agent when temper rolling black plate or sheet steel resulting in greater hardness and stiffness and with a corresponding loss in ductility. . NOTE: Black Plate in tempers T5 and T6 (R/B range 68/84) are temper rolled from Rephosphorized steel.

Residual Elements

Small quantities of elements unintentionally present in an alloy.

Residual Stress

Macroscopic stresses that are set up within a metal as the result of nonuniform plastic deformation. This deformation may be caused by cold working or by drastic gradients of temperature from quenching or welding.

Residuals

The impurities in mini-mill steel as the result of the mix of metals entering the process dissolved in obsolete scrap. Residuals are key concerns regarding the mini-mills' recent entry into the flat-rolled market, where high residuals can leave sheet steel too brittle for customer use.

Resilience

The tendency of a material to return to its original shape after the removal of a stress that has produced elastic strain.

Resistance Welding

A type of welding process in which the work pieces are heated by the passage of an electric current through the contact. Such processes include spot welding, seam or line welding and percussion welding. Flash and butt-welding are sometimes considered as resistance welding processes.

Resolution

The capacity of an optical or radiation system to separate closely spaced forms or entities; also, the degree to which such forms or entities can be discriminated.

Resulfurized Steel

Steel to which sulfur has been added in controlled amounts after refining. The sulfur is added to improve machinability.

Reversing Mill

The stand of rolls used to reduce steel sheet or plate by passing the steel back and forth between the rolls; the gap between the rolls is reduced after each pass.

Ribbon Wound

A term applied to a common method of winding strip steel layer upon layer around an arbor or mandrel.

Riffles

Waviness at the edge of sheet or strip.

Rimmed Steel

Low-carbon steel containing sufficient iron oxide to produce continuous evolution of carbon monoxide during ingot solidification, resulting in a case or rim of metal virtually free of voids.

Rimmed Steel

Low-carbon steel in which incomplete deoxidation permits the metal to remain liquid at the top of the ingot, resulting in the formation of a bottom and side rim of considerable thickness. The rim is of someWhat purer composition than the original metal poured. If the rimming action is stopped shortly after pouring of the ingot is completed, the metal is known as capped steel. Most steels below 0.15% carbon are rimmed steels. For the same carbon and manganese content rimmed steel is softer than killed steel.

Rimmed Steel

A low-carbon steel containing sufficient iron oxide to give a continuous evolution of carbon monoxide while the ingot is solidifying, resulting in a case or rim of metal virtually free of voids. Sheet and strip products made from the ingot have very good surface quality.

Ripple

(Defect) - A slight transverse wave or shadow mark appearing at intervals along the piece.

Rockwell Hardness (Test)

A standard method for measuring the hardness of metels. The hardness is expressed as a number related to the depth of residual penetration of a steel ball or diamond cone (brale) after a minor load of 10 kilograms has been applied to hold the penetrator in position. This residual penetration is automatically registered on a dial when the major load is removed from the penetrator. Various dial readings combined with different major loads, five scales designated by letters varying from A to H; the B and C scales are most commonly in use.

Rod

Round, thin semi-finished steel length that is rolled from a billet and coiled for further processing. Rod is commonly drawn into wire products or used to make bolts and nails. Rod trains (rolling facilities) can run as fast as 20,000 feet per minute‹more than 200 miles an hour.

Roentgen Rays

(See X-rays)

Roll Force Systems

Mill stands place considerable pressure on slabs, blooms and coils to further process the material. There are two general ways of applying the force to the steel < screw and hydraulic systems.
SCREW (INCLINE PLANE) This older method used the basic principle of the screw to adjust the space between the mill rolls. Because metal touches metal, these configurations will wear down over time and can cause quality problems.
HYDRAULIC (PANCAKE CYLINDER) This modern system uses fluid pressure to rapidly adjust the roll spacing several times per second. These minute, instantaneous adjustments allow for superior gauge tracking and higher-quality products.

Roll Forming

An operation used in forming sheet. Strips of sheet are passed between rolls of definite settings that bend the sheet progressively into structural members of various contours, sometimes called molded sections.

Rolled Edges

Finished edges, the final contours of which are produced by side or edging rolls. The edge contours most commonly used are square corners, rounded corners and rounded edge.

Rolled In Scale

A surface defect consisting of scale partially rolled into the surface of the sheet.

Roller Leveling

Leveling by passing flat stock through a machine having a series of small-diameter staggered rolls.

Rolling

Reducing the cross-sectional area of metal stock, or otherwise shaping metal products, through the use of rotating rolls.

Rolling Direction

(In rolled metal) - The direction, in the plane of the sheet, perpendicular to the axes of the rolls during rolling.

Rolling Mills

Equipment used for rolling down metal to a smaller size or to a given shape employing sets of rolls tie contours of which determine or fashion the product into numerous intermediate and final shapes, e.g., blooms, slabs, rails, bars, rods, sections, plates, sheets and strip.

Rotary Shear (Slitting Machine)

A cutting machine with sharpened circular blades or disc-like cutters used for trimming edges and slitting sheet and foil. NOTE: cutter discs are also employed in producing circles from flat sheets but with differently designed machines.

Rule Die Steel

A hardened and tempered medium high carbon spring steel strip sufficiently low in hardness to take moderately sharp bends without fracture, intended for manufacture into rule dies for the purpose of cutting or stamping fabrics, paper, cardboard, plastics, and metal foil into desired shape.

Back to Top

SAE

Abbreviation for Society of Automotive Engineers. This organization has specified common and alloy steels and copper base alloys in accordance with a numerical index system allowing approximation of the composition of the metal. The last two digits always indicate the carbon content, usually within 0.05%.

Salt Spray Test

An accelerated corrosion test in which the metal specimens are exposed to a fine mist of salt water solution either continuously or intermittently.

Scab

(Scabby) - A blemish caused on a casting by eruption of gas from the mold face or by uneven mold surface or occurring where the skin from a blowhole has partly burned away and is not welded.

Scale

The oxide of iron that forms on the surface of steel after heating.

Scaleless Blue

(See Black Oil Tempered Spring Steel)

Scallop

(See Earing)

Scalping

Machining the surface layers from ingots, billets and slabs before fabrication.

Scarf Joint

A butt joint in which the plane of the joint is inclined with respect to the main axes of the members.

Scarfing

Cutting surface areas of metal objects, ordinarily by using a gas torch. The operation permits surface defects to be cut from ingots, billets, or the edges of plate that is to be beveled for butt welding.

Scleroscope Hardness (Test)

A method for measuring the hardness of metals; a diamond-pointed hammer drops from a fixed distance through a tube onto the smoothed metal surface and the rebound measured. The scleroscope hardness value is empirically taken from the rebound distance, with specified high-carbon steel as 100.

Scleroscope Test

A hardness test where the loss in kinetic energy of a falling metal tup, absorbed by indentation upon impact of the tup on the metal being tested, is indicated by the height of rebound.

Scrap (Ferrous)

Ferrous (iron-containing) material that generally is remelted and recast into new steel. Integrated steel mills use scrap for up to 25% of their basic oxygen furnace charge; 100% of the mini-mills' raw material for their electric furnaces generally is scrap.
HOME SCRAP Waste steel that is generated from within the steel mill, through edge trimming and rejects. It normally is sent directly back to the furnace.
PROMPT (INDUSTRIAL) SCRAP Excess steel that is trimmed by the auto and appliance stampers and auctioned to scrap buyers as factory bundles. This is a high-quality scrap as the result of its low-residual content and consistent chemistry.
OBSOLETE SCRAP Iron-bearing trash. Automobile hulks, worn-out refrigerators and useless storage tanks, for example, can be recovered from the junkyard and remelted. The residual impurity of such scrap normally relegates obsolete scrap to the mini-mills ( No. 1 Heavy Melt).

Scrap Substitute

Raw material that can be charged in place of scrap in electric arc furnaces and basic oxygen furnaces. Scrap substitutes include, among others, DRI, HBI, iron carbide, and pig iron.

Scratch Brushed Finish

Finish obtained by mechanically brushing the surface with wire bristle brushes, by buffing with greaseless compound or by cold rolling with wire bristled rolls on scratch etched finish.

Seam

On the surface of metal, an unwelded ford or lap which appears as a crack, usually resulting from a defect obtained in casting or in working.

Seam (A defect.)

On the surface of metal a crack that has been closed but not welded; usually produced by some defect either in casting or in working, such as blowholes that have become oxidized or folds and laps that have been formed during working. Similar to cold shut and laminations.

Seam Welding

An electric-resistance type of welding process, in which the lapped sheet is passed between electrodes of the roller type while a series of overlapping spot welds is made by the intermittent application of electric current.

Seamless Pipe

Pipe made from a solid billet, which is heated, then rotated under extreme pressure. This rotational pressure creates an opening in the center of the billet, which is then shaped by a mandrel to form pipe.

Secondary Hardening

Tempering certain alloy steels at certain temperatures so that the resulting hardness is greater than that obtained by tempering the same steel at some lower temperature for the same time.

Secondary Steel

Steel that does not meet the original customer's specifications because of a defect in its chemistry, gauge or surface quality. Mills must search to find another customer (that can accept the lower quality) to take the off-spec steel at a discount. While secondary will not affect the reported yield, margins will suffer.

Seconds

The designation given to sheet or strip that has imperfections in moderate degree or extent, which may be classified in two general groups -- imperfections in the base material, or other manufacturing defects. This term not used in connection with non-ferrous alloys.

Segment Steel

Used for laminated piston rings. Carbon content about .60%. Hardened and blue tempered with round edges. Hardness usually Rockwells 30 N 68 to 71, widths vary from .058 to .163 and thicknesses are .020, .024 and .030.

Segregation

Nonuniform distribution of alloying elements, impurities or phases.

Segregation

In an alloy, concentration of alloying elements at specific regions, usually as a result of the primary crystallization of one phase with the subsequent concentration of other elements in the remaining liquid.

Segregation Banding

In homogeneous distribution of alloying elements aligned on filaments or plates parallel to the direction of working.

Self Diffusion

The spontaneous movement of an atom to a new site in a crystal of its own species.

Self-Hardening Steel

A steel containing sufficient carbon or alloying element, or both, of form martensite either through air hardening or, as in welding and induction hardening, through rapid removal of heat from a locally heated portion by conduction into the surrounding cold metal.

Semi-finished Steel

Steel shapes—for example, blooms, billets or slabs—that later are rolled into finished products such as beams, bars or sheet. Sendzimir Mill (Z-mill) WHAT Compact mill used for rolling cold coils of stainless steel in order to make the steel thinner, smoother, and stronger.
WHY To control the thickness of steel better at lower capital cost, and to roll thinner sheets and strips.
HOW Stainless steel sheet or strip passes between a matching pair of small work rolls with extremely smooth surfaces, heavily reinforced by clusters of back-up rolls. The rolls reduce the steel to the desired thickness. Service Center A catchall name for an operation that buys steel, often processes it in some way and then sells it in a slightly different form. A service center is distinguished from an end-user by the fact that, unlike an end-user, a service center sells steel, not a fabricated product. Service centers are manufacturers to the extent that they add labor to steel by providing a service.

Semikilled Steel

Steel that is incompletely deoxidized and contains sufficient dissolved oxygen to react with the carbon to form carbon monoxide and thus offset solidification shrinkage.

Semi-Steel

Cast iron (not steel) of high quality, obtained by using a large percentage of steel scrap with the pig iron.

Sendzimir Mill

A mill having two work rolls of 1 to 2 1/2-in diam. each, backed up by two rolls twice that diameter and each of these backed up by bearings on a shaft mounted eccentrically so that rotating it increases the pressure between bearings and backup rolls.

Shape Correcting

Rolling, heating and quenching steel sheets often affect the dimensions of the steel. Levelers, temper mills and edge trimmers rework the processed steel to match customer specifications.

Shear Bands (deformation)

Bands in which deformation has been concentrated inhomogeneously in sheets that extend across regional groups of grains. Usually only one system is present in each regional group of grains, different systems being present in adhoining groups. The bands are noncrystallographic and form on planes of maximum shear stress (55(degrees) to the compression direction). They carry most of the deformation at large strains. Compare microbands.

Shear

A type of cutting operation in which the metal object is cut by means of a moving blade and fixed edge or by a pair of moving blades that may be either flat or curved.

Shear Crack

A diagonal, transgranular crack caused by shear stresses.

Shear Steel

Steel produced by forge welding together several bars of blister steel, providing a more homogeneous product.

Shear Strength

The stress required to produce fracture in the plane of cross section, the conditions of loading being such that the directions of force and of resistance are parallel and opposite although their paths are offset a specified minimum amount.

Shearing

If the edges of sheet and strip are not controlled during reduction, they must be trimmed parallel by shears. This process may be performed by either the steel mill or steel processor to match customer needs.

Sheet Steel

Thin, flat-rolled steel. Coiled sheet steel accounts for nearly one-half of all steel shipped domestically and is created in a hot-strip mill by rolling a cast slab flat while maintaining the side dimensions. The malleable steel lengthens to several hundred feet as it is squeezed by the rolling mill. The most common differences among steel bars, strip, plate, and sheet are merely their physical dimensions of width and gauge (thickness).
Product Classification by Size
Source: Smith Barney Inc./Salomon Brothers Inc.

Shell Molding

Forming a mold from thermosetting resin-bonded sand mixtures brought in contact with pregeated (300 to 500 (degrees) F) metal patterns, resulting in a firm shell with a cavity corresponding to the outline of the pattern. Also called Croning process.

Shielded-Arc Welding

Arc welding in which the arc and the weld metal are protected by a gaseous atmosphere, the products of decomposition of the electrode covering, or a blanket of fusible flux.

Shim

A thin flat hard metal strip produced to close tolerances; used primarily for tool, die and machine alignment purposes. In steel there are four general types: (1) Low Carbon Rockwell B 80/100; (2) Hard Rolled High Carbon Rockwell C 28/33. (3) Hardened and Tempered Spring Steel Rockwell C 44/51; (4) Austenitic Stainless Steel Rockwell C 35/45. Brass shim of commercial quality is also used and most generally specified is 2 Nos. Hard but may be 4 Nos. Hard.

Shore Hardness (Test)

(See Scleroscope Hardness)

Short

Brittle.

Short Terne

A term applying to terne coated (Lead and Tin) sheets with reference to Base Box sizes (14 x 20) Refer to terne plate.

Shortness

A form of brittleness in metal. It is designed as cold, hot, and red, to indicate the temperature range in which the brittleness occurs.

Shortness

A form of brittleness in metal. It is designated as cold, hot, and red, to indicate the temperature range in which the brittleness occurs.

Shot Blasting

Cleaning surface of metal by air blast, using metal as a result of solidification shrinkage and the progressive freezing of metal towards the center.

Shredded Scrap

Fist-sized, homogenous pieces of old automobile hulks. After cars are sent through a shredder, the recyclable steel is separated by magnets. Mini-mills consume shredded scrap in their electric arc furnace operations.

Shrinkage Cavity

A void left in cast metals as a result of solidification shrinkage and the progressive freezing of metal towards the center.

Silicon

Chemical symbol Si. Element No. 14 of the periodic system; atomic weight 28.06. Extremely common element, the major component of all rodks and sands; its chemical reactions, However, are those of a metalloid. Used in metallurgy as a deoxidizing scavenger. Silicon is present, to some extent, in all steels, and is deliberately added to the extent of approximately 4% for electric sheets, extensively used in alternating current magnetic circuits. Silicon cannot be electrodeposited.

Silicon Electrical Steel

A type of specialty steel created by introducing silicon during the steelmaking process. Electrical steel exhibits certain magnetic properties, which make it optimum for use in transformers, power generators and electric motors.
GRAIN-ORIENTED The metal's grain runs parallel within the steel, permitting easy magnetization along the length of the steel. Although grain-oriented steel may be twice as expensive to produce, its magnetic directional characteristics enable power transformers, made from this metal, to absorb less energy during operation.
NON-GRAIN-ORIENTED Because there is no preferential direction for magnetization, non-grain-oriented steel is best used in rotating apparatus such as electric motors.

Silicon Steel

Steel usually made in the basic open-hearth or electric furnace, with about 0.50-5.% silicon, other elements being usually dept as low as possible. Because of high electrical resistance and low hysterisis loss, silicon sheet and strip are standard in electric magnet manufacture.

Siliconizing

Diffusing silicon into solid metal, usually steel, at an elevated temperature.

Silky Fracture

A steel fracture that has a very smooth fine grain or silky appearance.

Silver Solders

Alloys of silver, copper, sinc and other metals, melting between 650 and 875 (degrees) C. used for making strong yet moderately ductile joints that resist corrosion.

Single-Action Press

A forming press that operates with a single function, such as moving a punch into a die with no simultaneous action for holding down the bland or ejecting the formed work.

Sinker Steel

Used for making sinkers in hosiery making machinery. Supplied both hardened and tempered and cold rolled and annealed. Usually extra precision rolled and extra flat. Carbon content about 1.25.

Sinkhead

A reservoir insulated to retain heat and to hod excess molten metal on top of an ingot mold, in order to feed the shrinkage of the ingot. Also called shrink head or feeder head. (See Hot Top)

Sintered Carbide

Composite, containing carbides of extremely refractory metals, such as tungsten, tantalum, titanium, etc., cemented together by a relatively low-melting metal, such as cobalt acing as a matrix.

Sintering

Converting powder into a continuous mass by heating to a temperature considerably below fusion, usually after preliminary compacting by pressure.

Sintering

A process that combines iron-bearing particles, once recovered from environmental control filters, into small pellets. Previously, these materials were too fine to withstand the air currents of the smelting process and were thrown away. The iron is now conserved because the chunks can be charged into the blast furnace (see Agglomerating Processes).

Skelp

Steel that is the entry material to a pipe mill. It resembles hot-rolled strip, but its properties allow for the severe forming and welding operations required for pipe production.

Skin

A thin surface layer that is different from the main mass of a metal object, in composition, structure or other characteristics.

Skull

A layer of solidified metal or dross on the wall of a pouring vessel often when metal has been poured.

Slab

The most common type of semi-finished steel. Traditional slabs measure 10 inches thick and 30-85 inches wide (and average about 20 feet long), while the output of the recently developed "thin slab" casters is approximately two inches thick. Subsequent to casting, slabs are sent to the hot-strip mill to be rolled into coiled sheet and plate products.

Slack Quenching

The process of hardening steel by quenching from the austenitizing temperature at a rate slower than the critical cooling rate for the particular steel, resulting in incomplete hardening and the formation of one or more transformation products in addition to or instead of martensite.

Slag

The impurities in a molten pool of iron. Flux such as limestone may be added to foster the congregation of undesired elements into a slag. Because slag is lighter than iron, it will float on top of the pool, where it can be skimmed.

Slip

Plastic deformation by irreversible shear displacement of one part of a crystal relative to another in a definite crystallographic direction and on a definite crystallographic plane.

Slip Direction

The crystallographic direction in which translation of slip takes place.

Slip Line

Trace of a slip plane on a viewing surface.

Slip Plane

The crystallographic plane on which slip occurs in a crystal.

Slit

When two or more widths are obtained from the hot rolled substrate width. The slitting operation results in a cut edge.

Slit Edges

The edges of sheet or strip metal resulting from cutting to width by rotary slitters.

Slitting

Cutting a sheet of steel into narrower strips to match customer needs. Because steel mills have limited flexibility as to the widths of the sheet that they produce, service centers normally will cut the sheet for the customer.

Sliver (defect)

Loose metal piece rolled down onto the surface of the metal during the rolling operations.

Soaking

Prolonged heating of a metal at selected temperature.

Soft Skin Rolled Temper (No. 4 Temper)

In low carbon-rolled strip steel, soft and ductile. Produced by subjecting annealed strip to a pinch pass or skin rolling (a very light rolling).

Solder Embrittlement

Reduction in ductility of a metal or alloy, associated with local penetration by molten solder along grain boundaries.

Soldering

Joining metals by fusion of alloys that have relatively low melting points -- most commonly, lead-base or tin-base alloys, which are the soft solders. Hard solders are alloys that have silver, copper, or nickel bases and use of these alloys with melting points higher than 800 (degrees) F. is generally termed brazing.

Solid Solution

A solid crystalline phase containing two or more chemical species in concentrations that may vary between limits imposed by phase equilibrium.

Solidus

In a constitutional diagram, the locus of points representing the temperatures at which various components finish freezing on cooling or begin to melt on heating.

Solute

The component of either a liquid or solid solution that is present to the lesser or minor extent; the component that is dissolved in the solvent.

Solution Heat Treatment

A heat treatment in which an alloy is heated to a suitable temperature, held at that temperature long enough to cause one or more constituents to enter into solid solution, and then cooled rapidly enough to hold these constituents in solution.

Solution Heat Treatment

Heating an alloy to a suitable temperature, holding at that temperature long enough to allow one or more constituents to enter into solid solution, and then cooling rapidly enough to hold the constituents in solution. The alloy is left in a supersaturated, unstable state, and may subsequently exhibit quench aging.

Solution Heat Treatment

A process in which an alloy is heated to a suitable temperature long enough to allow a certain constituent to enter into solid solution and is then cooled rapidly to hold the constituent in solution. The metal is left in a supersaturated, unstable state and may subsequently exhibit age hardening.

Solvent

The component of either a liquid or solid solution that is present to the greater or major extent; the component that dissolves the solute.

Solvus

In a phase or equilibrium diagram, the locus of points representing the temperature at which solid phases with various compositions coexist with other solid phases; that is, the limits of solid solubility.

Sorbite

Structure of steel, resulting from the tempering of martensite. In a truly sorbitic structure, the cementite is completely dispersed in the matrix. The trend is to call this structure tempered martensite.

Sorbite (obsolete)

A fine mixture of ferrite and cementite produced either by regulating the rate of cooling of steel or tempering steel after hardening. The first type is very fine pearlite difficult to resolve under the microscope; the second type is tempered martensite.

Sorbitic Pearlite

Structure of steel resulting, on cooling under the proper conditions, from the decomposition of austenite; has a fine, lamellar appearance.

Space Lattice (crystal)

A system of equivalent points formed by the intersections of three sets of planes parallel to pairs of principal axes; the space lattice may be thought of as formed by the corners of the unit cells.

Space-Centered (concerning space lattices)

Body-centered.

Spalling

The cracking and flaking of particles out of a surface.

Spangle

The spangle of a hot-dip coated sheet surface is the visual manifestation of the grains that form within the coating when it solidifies as the sheet emerges from the pot of molten coating metal. The spangle or grain varies in size, brightness and surface relief, depending upon a number of factors, most of which are related to the composition of the coating and cooling practices.

Special Bar Quality (SBQ)

SBQ represents a wide variety of higher-quality carbon and alloy bars that are used in the forging, machining and cold-drawing industries for the production of automotive parts, hand tools, electric motor shafts and valves. SBQ generally contains more alloys than merchant quality and commodity grades of steel bars, and is produced with more precise dimensions and chemistry.

Specialty Steel

Category of steel that includes electrical (see Silicon Electrical Steel), alloy (see Alloy Steel), stainless (see Stainless Steel) and tool (see Tool Steels) steels.

Specialty Tube

Refers to a wide variety of high-quality custom-made tubular products requiring critical tolerances, precise dimensional control and special metallurgical properties. Specialty tubing is used in the manufacture of automotive, construction and agricultural equipment, and in industrial applications such as hydraulic cylinders, machine parts and printing rollers. Because of the range of industrial applications, the market typically follows general economic conditions.

Specific Gravity

A numerical value representing the weight of a given substance as compared with the weight of an equal volume of water, for which the specific gravity is taken as 1.0000.

Spectograph

An optical instrument for determining the presence or concentration of minor metallic constituents in a material by indicating the presence and intensity of specific wave lengths of radiation when the material is thermally or electrically excited.

Spectograph (X-rays)

An instrument using an extended surface -- a photographic plate or film, or a fluorescent screen -- for receiving the X-ray diffraction pattern.

Spelter (Prime Western Spelter)

A low-grade of Virgin Zinc containing approximately 98% Zinc used in Galvanizing processes.

Speroidizing

Heating and cooling to produce a spheroidal or globular form of carbide in steel. Spheroidizing methods frequently used are: 1. Prolonged holding at a temperature just below Ae1. . 2. Heating and cooling alternately between temperatures that are just below Ae1. . 3. Heating to temperature above Ae1 or Ae3 and then cooling very slowly in the furnace or holding at a temperature just below Ae1. . 4. Cooling at a suitable rate from the minimum temperature at which all carbide is dissolved, to prevent the reformation of a carbide network, and then re-heating in accordance with methods 1 or 2 above. (Applicable to hypereutectoid steel containing a carbide network.

Speroidizing Annealing

A subcritical annealing treatment intended to produce spheroidization of cementite or other carbide phases.

Spheroidized Structure

A microstructure consisting of a matrix containing spheroidal particles of another constituent.

Spheroidizing

Any process of prolonged heating and slow cooling of steel which will convey the carbide content into rounded or spheroid form.

Spheroidizing

Heating and cooling to produce a spheroidal or globular form of carbide in steel.

Spiegel

High-manganese pig iron, containing 15-30% manganese, approximately 5% carbon, and less than 1% silicon used in the manufacture of steel by the Bessemer, or basic open-hearth process.

Spinning

The procedure of making sheet metal discs into hollow shapes by pressing the metal against a rotating form (spinning chuck) by a tool.

Spot Market

Sales for delivery in less than three months.

Spot Welding

An electric-resistance welding process in which the fusion is limited to a small area. The pieces being welded are pressed together between a pair of water-cooled electrodes through which an electical current is passed during a very short interval so that fusion occurs over a small area at the interface between the pieces.

Spot Welding

Welding of lapped parts in which fusion is confined to a relatively small circular area. It is generally resistance welding, but may also be gas-shielded tungsten-arc, gas-shielded metal-arc, or submerged-arc welding.

Spring Steel

Steel, normally of the high-carbon or alloy type, used in the manufacture of springs, lending itself to appropriate heat treatment; usually made is the open hearth or electric furnace.

Spring Steel Strip

Any of a number of strip steels produced for use in the manufacture of steel springs or where high tensile properties are required marketed in the annealed state, hard rolled or as hardened and tempered strip.

Spring Temper

In brass mill terminology, Spring Temper is eight numbers hard or 60.50% reduction.

Spring-Back

An indicator of elastic stresses, frequently measured as the increase in diameter of a curved strip after removing it from the mandrel about which it was held. The measurement is employed as an indicator of the extent of recovery or relief of residual stresses that has been achieved by the transformation of elastic strain to plastic strain during heating or stress relieving.

Stabilizing Anneal

A treatment applied to austentic stainless steels that contain titanium or columbium. This treatment consists of heating to a temperature below that of a full anneal in order to precipitate the maximum amount of carbon at titanium carbide or columbium carbide. This eliminates precipitation at lower temperatures, which might reduce the resistance of the steel to corrosion.

Stablizing Treatment

Any treatment intended to stabilize the structure of an alloy of the dimensions of a part. (1) Heating austenitic stainless steels that contain titanium, columbium, or tantalum to a suitable temperature below that of a full anneal in order to inactivate the maximum amount of carbon by precipitation as a carbide of titanium, columbium, or tantalum. (2) Transforming retained austenite in parts made from tool steel. (3) Precipitating a constituent from a nonferrous solid solution to improve the workability, to decrease the tendency of certain alloys to age harden at room temperature, or to obtain dimensional stability.

Stain Finish

(See Scratch Brushed Finish)

Stainless Steel

The term for grades of steel that contain more than 10% chromium, with or without other alloying elements. Stainless steel resists corrosion, maintains its strength at high temperatures, and is easily maintained. For these reasons, it is used widely in items such as automotive and food processing products, as well as medical and health equipment. The most common grades of stainless steel are:
TYPE 304 The most commonly specified austenitic (chromium-nickel stainless class) stainless steel, accounting for more than half of the stainless steel produced in the world. This grade withstands ordinary corrosion in architecture, is durable in typical food processing environments, and resists most chemicals. Type 304 is available in virtually all product forms and finishes.
TYPE 316 Austenitic (chromium-nickel stainless class) stainless steel containing 2%-3% molybdenum (whereas 304 has none). The inclusion of molybdenum gives 316 greater resistance to various forms of deterioration.
TYPE 409 Ferritic (plain chromium stainless category) stainless steel suitable for high temperatures. This grade has the lowest chromium content of all stainless steels and thus is the least expensive.
TYPE 410 The most widely used martensitic (plain chromium stainless class with exceptional strength) stainless steel, featuring the high level of strength conferred by the martensitics. It is a low-cost, heat-treatable grade suitable for non-severe corrosion applications.
TYPE 430 The most widely used ferritic (plain chromium stainless category) stainless steel, offering general-purpose corrosion resistance, often in decorative applications.

Stamping

A term used to refer to various press forming operations in coining, embossing, blanking, and pressing.

Statistical Process Control (SPC)

A technique used to predict when a steelmaking function's quality may deteriorate. By tightly monitoring the product's variance from specifications, the operator can determine when to apply preventative maintenance to a machine before any low-quality (secondary) steel is produced.

Steam Blued

(See Bluing)

Steckel Mill

A reversing steel sheet reduction mill with heated coil boxes at each end. Steel sheet or plate is sent through the rolls of the reversing mill and coiled at the end of the mill, reheated in the coil box, and sent back through the Steckel stands and recoiled. By reheating the steel prior to each pass, the rolls can squeeze the steel thinner per pass and impart a better surface finish.

Steel

An iron-base alloy usually containing carbon and other alloying elements. In carbon steel and low-alloy steel, the maximum carbon content is about 2.0%; in high-alloy steel, about 2.5%. The dividing line between low-alloy and high-alloy steels is generally regarded as the 5% level of total metallic alloying elements. Steel is differentiated from two general classes of iron - namely, cast irons, which have high carbon concentrations, and relatively pure irons, which have low carbon concentrations.

Steel

An iron-base alloy, malleable in some temperature range as initially cast, containing manganese, usually carbon, and often-other alloying elements. In carbon steel and low-alloy steel, the maximum carbon is about 2.0%; in high-alloy steel, about 2.5%. The dividing line between low-alloy and high-alloy steels is generally regarded as being at about 5% metallic alloying elements. Steel is to be differentiated from two general classes of irons: the cast irons, on the high-carbon side, and the relatively pure irons such as ingot iron, carbonyl iron, and electrolytic iron, on the low-carbon side. In some steels containing extremely low carbon, the manganese content is the principal differentiating factor, steel usually containing at least 0.25%; ingot iron contains considerably less.

Steel Intensity

The amount of steel used per unit of gross domestic product. Intensity reflects the secular demand for steel, as opposed to cyclical demand. The amount of steel used in vehicles and the popularity of alternative materials affect the intensity, or How much steel is needed per unit produced. The state of the economy, However, determines the number of units.

Steel Service Center Inventories

End-of-period material stocks reported by the Steel Service Center Institute (SSCI).

Steel Strapping

Banding and packaging material that is used to close and reinforce shipping units, such as bales, boxes, cartons, coils, crates, and skids.

Steel-Intensive Products

Consumer products such as automobiles and appliances that, because so much of their weight is from steel, exhibit a high demand correlation with steel.

Sterling Silver

A silver alloy containing at least 95.2% Ag, the remainder being unspecified but usually copper.

Sticker

Steel sheets or strip adhering. Usually by fusion spots caused by overheating during box annealing.

Straight-Chrome

An iron alloy. A term indicating a group of stainless steels the principal alloying element of which is chromium in varying amounts from 4.00 to 27.00%.

Strain

A measure of the change in the size or shape of a body, referred to its original size or shape. Linear strain is the change per unit length of a linear dimension. True strain (or natural strain) is the natural logarithm of the ratio of the length at the moment of observation to the original gauge length. Conventional strain is the linear strain referred to the original gauge length. Shearing strain (or shear strain) is the change in angle (expressed in radians) between two lines originally at right angles. When the term strain is used alone it usually refers to the linear strain in the direction of the applied stress.

Strain

Deformation produced on a body by an outside force.

Strain Aging

Aging induced by cold work.

Strain Hardening

An increase in hardness and strength caused by plastic deformation at temperatures below the recrystallization range.

Strength

Properties related to the ability of steel to oppose applied forces. Forms of strength include withstanding imposed loads without a permanent change in shape or structure and resistance to stretching.

Stress

Deforming force to which a body is subjected or the resistance which the body offers to deformation by the force.

Stress Corrosion Cracking (SCC)

Slow growth of cracks in stainless steel caused by the combined effect of mechanical stress and exposure to a corrosive environment.

Stress Relief

Low temperature annealing for removing internal stresses, such as those resulting on a metal from work hardening or quenching.

Stress Relieving

Heating to a suitable temperature, holding long enough to reduce residual stresses and then cooling slowly enough to minimize the development of new residual stresses.

Stress-Corrosion Cracking

Failure by cracking under the combined action of corrosion and stress, either external (applied) or internal (residual). Cracking may be either intergranular or transgranular, depending on the metal and the corrosive medium.

Stress-Rupture Test

A tension test performed at constant temperature, the load being held at such a level as to cause rupture. Also known as creep-rupture test.

Stretch Forming

A process of forming panels and cowls of large curvature by stretching sheet over a form of the desired shape. This method is more rapid than hammering and beating.

Stretcher Leveling

Leveling where a piece of metal is gripped at each end and subjected to a stress higher than its yield strength to remove warp and distortion. Sometimes called patent leveling.

Stretcher Leveling

A method of making metal sheet or strip dead flat by stretching.

Stretcher Straightening

A process for straightening rod, tubing, and shapes by the application of tension at the ends of the stock. The products are elongated a definite amount to remove warpage.

Stretcher Strains

Elongated markings that appear on the surface of some materials when deformed just past the yield point. These markings lie approximately parallel to the direction of maximum shear stress and are the result of localized yielding Same as Luders lines.

Stretcher Strains

Long vein-like marks appearing on the surface of certain metals, in the direction of the maximum shear stress, when the metal is subjected to deformation beyond the yield point. Also termed Luders Lines. (Not a defect in No. 5 dead soft temper.)

Strip

Thin, flat steel that resembles hot-rolled sheet, but it is normally narrower (up to 12 inches wide) and produced to more closely controlled thicknesses. Strip also may be cut from steel sheet by a slitting machine (see Sheet Steel).

Strip Steel (cold rolled)

A flat cold rolled steel product (Other than Flat Wire) 23 15/16 and narrower; under .250 in thickness, which has been cold reduced to desired decimal thickness and temper on single stand, single stand reversing, or tandem cold mills in coil form from coiled hot rolled pickled strip steel.

Structurals

Steel product group that includes I-beams, H-beams, wide-flange beams and sheet piling. These products are used in the construction of multi-story buildings, industrial buildings, bridge trusses, vertical highway supports, and riverbank reinforcement.

Structural Steel

When this term is applied to steel sheet, it refers to the designation that is used for steel sheet that is produced to meet a specific level of strength and formability. The formability is expressed as percent elongation in a tensile test. Structural Steel is typically used for applications where the strength of the sheet is an important design criterion, i.e., load-bearing applications.

Structure

The arangement of parts; in crystals, expecially, the shape and dimension of the until cell, and the number, kinds and positions of the atoms within it.

Sub-boundary Structure (subgrain structure)

A network of low-angle boundaries (usually with misorientations or less than one degree) within the main grains of a microstructure.

Subcritical Annealing

An annealing treatment in which a steel is heated to a temperature below the A1 temperature and then cooled slowly to room temperature.

Subgrain

A portion of a crystal or grain slightly different in orientation from neighboring portions of the same crystal. Generally, neighboring subgrains are separated by low-angle boundaries.

Substitutional Solid Solution

A solid solution in which the solvent and solute atoms are located randomly at the atom sites in the crystal structure of the solution.

Substrate

The layer of metal underlying a coating, regardless of whether the layer is base metal.

Substrate

Raw material used as an input for steel processing: For example, hot-rolled steel is the substrate for cold-rolling operations.

Sulfar

(Chemical Symbol S.) - Element No. 16 of the periodic system; atomic weight 32.06. Non-metal occurring in a number of allotropic modifications, the most common being a pale-yellow brittle solid. In steel most commonly encountered as an undesired contaminant. However, it is frequently deliberately added to cutting stock to increase machinability.

Superalloy

An alloy developed for very high temperature service where relatively high stresses (tensile, thermal, vibratory, and shock) are encountered and where oxidation resistance is frequently required.

Supercooling

Cooling to a temperature below that of an equilibrium phase transformation without the transformation taking place.

Superficial Rockwell Hardness Test

Form of Rockwell hardness test using relatively light loads which produce minimum penetration. Used for determining surface hardness or hardness of thin sections or small parts, or where large hardness impression might be harmful.

Back to Top

T-Bend 0-,1-,2-, etc.

A mechanical operation wherein a sheet sample is bent back upon itself with the inside bend radius specified in terms of the sheet thicknesses. Thus a 2-T Bend is a bend with an inside radius equivalent to two times the thickness of the metal sheet being tested.

Taconite

WHAT Natural mineral containing less than 30% iron. It is the primary ore used in blast furnaces. WHY Domestic supplies of iron-rich ores (greater than 50% iron) were largely depleted in the 1940s, so integrated steel companies now process the lower-grade taconite to make it useful.

Tailored Blanks

A section of sheet or strip that is cut-to-length and trimmed to match specifications for the manufacturer's stamping design for a particular part. Because excess steel is cut away (to save shipping costs), all that remains for the stamper is to impart the three-dimensional shape with a die press (see Blanking).

Tandem Coating Line

A continuous coil coating line having two or more coating machines and curing or baking ovens in the line so it is capable of applying and curing two coats of paint in one pass through the line

Tandem Mill

A type of cold-rolling mill, the tandem mill imparts greater strength, a uniform and smoother surface, and reduced thickness to the steel sheet. Unlike the original single-stand mills, a tandem mill rolls steel through a series of rolls (generally three to five in a row) to achieve a desired thickness and surface quality.

Tapping

Transferring molten metal from melting furnace to ladle.

Tarnish

Surface discoloration on a metal, usually from a thin film of oxide or sulfide.

Teeming

Pouring molten metal from a ladle into ingot molds. The term applies particularly to the specific operation of pouring either iron or steel into ingot molds.

Temper

(1) In heat treatment, re-heating hardened steel or hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing the hardness and increasing the toughness. The process also is sometimes applied to normalized steel. (2) In tool steels, temper is sometimes used, but inadvisedly, to denote the carbon content. (3) In nonferrous alloys and in some ferrous alloys (steels that cannot be hardened by heat treatment), the hardness and strength produced by mechanical or thermal treatment, or both, and characterized by a certain structure, mechanical properties, or reduction in area during cold working.

Temper

The state of or condition of a metal as to its hardness or toughness produced by either thermal treatment or heat treatment and quench or cold working or a combination of same in order to bring the metal to its specified consistency. Each branch of the metal producing industry has developed its own system of temper designates. In flat rolled products including sheet and strip steel, tin mill products, stainless strip, aluminum sheet and copper base alloy strip; they are sHown as follows:
ALUMINUM SHEET - (See Aluminum)
COPPER BASE ALLOYS (Cold Rolled) - B S Gage Numbers.
NOTE - Hardness is indicated condition while hardness varies with alloy changes.

TemperHardness
AnnealedCommercially Soft
Quarter HardOne Number Hard
Half HardTwo Numbers Hard
Hard TemperFour Numbers Hard
Extra HardSix Numbers Hard
Spring TemperEight Numbers Hard
Extra Spring TemperTen Numbers Hard

SHEET STEEL (Low Carbon Cold Rolled) - Temper Classifications.

TemperRockwell
Full Hard.069 and thinner B 90 min.
 .070 and thinner B 84 min.
Half HardApprox. R/B 70/85
Quarter HardApprox. R/B 60/75
Soft Commercial QualityApprox. R/B 66 max.
Drawing QualityApprox. R/B 55 max.

STAINLESS STRIP STEEL (Cold Rolled Temper Classification) - Type 301.
NOTE - The various stainless strip tempers are based on specified minimum values for tensile strength or yield strength or both. However, because of custom, both distributors and customers alike rely on approximate Rockwell readings for temper classification. To illustrate:

Temper (Type 301)RockwellTensile Psi
SoftApprox. B 75/85110,000 Min.
Quarter HardApprox. C 25/30125,000 Min.
Half HardApprox. C 30/35150,000 Min.
Three Quarters HardApprox. C 35/40175,000 Min.
Full HardApprox. C 40/45185,000 Min.
Extra Hard (Type 301)Approx. C 45 min200,000 Min.
Type 430 SoftApprox. B 75/8575/85,000

STRIP STEEL (Low Carbon Cold Rolled) - Temper Classifications.

TemperRockwellMeans Tensile
No. 1 Full Hard.069 and thinner B 90 min.80,000
 .070 and thicker B 84 min.80,000
No.2 Half hardB 70/8564,000
No.3 Quarter HardB 60/7554,000
No.4 Skin RolledB 65 max.48,000
No. 5 Dead SoftB 55 max. 

TEMPERED SPRING STEELS (Strip) - Temper indication is to Rockwell Hardness only.
TIN MILL PRODUCTS (Steel) Temper Classifications - NOT STANDARDIZED. FOR INFORMATION ONLY. (Not to be confused with the Cold Rolled Strip Steel Temper Numbering System wherein No. 1 Temper indicates Full Hard, while in the TIN MILL Product Numbering System No. 1 Temper indicates a soft condition.) The following Rockwell ranges are approx. only.

Temper-NumberRockwell - 30 T ScaleRockwell B Scale
No. 1 TemperAim at 46/52Aim at 45/53
No. 2 TemperAim at 50/56Aim at 51/59
No. 21/2 TemperAim at 52/58Aim at 53/62
No. 3 TemperAim at 54/60Aim at 56/66
No.4 TemperAim at 58/64Aim at 62/71
*No. 5 TemperAim at 62/68Aim at 68/77
*No. 6 TemperAim at 62/73Aim at 75/84

*NOTE: Tempers 5 and 6 are temper rolled from rephosphorized steel in order to develop desired hardness and stiffness. The above temper classifications are used principally by producing mills and can manufacture but are not in general use in the sheet and strip industry.

Tension Leveling

A mechanical operation wherein steel sheet, in coil form, is processed on a unit that stretches the product beyond its yield point to impart permanent deformation. The stretching operation assists to flatten the sheet. Tension leveling is considered the optimum process to achieve superior flatness characteristics.

Telescoping

Transverse slipping of successive layers of a coil so that the edge of the coil is conical rather than flat.

Temper Brittleness

A reversible increase in the ductile-brittle transition temperature in steels heated in, or slowly cooled through, the temperature range from about 700 to 1100 F (375 to 575 C).

Temper Brittleness

Brittleness that results when certain steels are held within, or are cooled slowly through, a certain range of temperature below the transformation range. The brittleness is revealed by notched-bar impact tests at or below room temperature.

Temper Mill

A type of cold-rolling mill, usually with only one or two stands, that finishes cold-rolled, annealed sheet steel by improving the finish or texture to develop the required final mechanical properties. By changing the rolls of the temper mill, steel can be shipped with a shiny, dull or grooved surface.

Temper Rolling

Subjecting metal sheet or strip to a slight amount of cold rolling following annealing (usually 1/2 to 1 1/2%) to forestall stretcher strains. Also termed Pinch Pass or Skin Rolled.

Temper Rolling

Light cold rolling of sheet steel. The operation is performed to improve flatness, to minimize the formation of stretcher strains, and to obtain a specified hardness or temper.

Tempered and Polished Spring Steel Strip

90/1.03 carbon range (Also known as clock spring steel.) This product, while similar to general description under heading of Tempered Spring Steel Strip, is manufactured and processed with great and extreme care exercised in each step of its production. Manufactured from carbon range of .90/1.03 with Rockwell range C 48/51. Clock spring quality has been ground and polished with edges dressed. It is usually supplied hard blue in color and has a wide range of uses, such as coiled and flat mechanical springs, ignition vibrator springs, springs for timing devices, springs for the electric and electonic fields, steel tapes, rules, etc.

Tempered Spring Steel Strip

Any medium or high carbon (excluding clock spring) strip steel of spring quality which has been hardened and tempered to meet specifications. Where specification calls for blue or straw color, same is accomplished by passing through heat prepared at proper temperature depending on color required. Blue is developed at approximately 600 (degrees) F.

Tempering

In heat treatment, re-heating hardened steel to some temperature below the A1 temperature for the purpose of decreasing hardness and/or increasing toughness. The process also is sometimes applied to normalized steel.

Tempering (Also termed 'drawing.')

A process of re-heating quench-hardened or normalized steel to a temperature below the transformation range and then cooling at any rate desired. The primary purpose of tempering is to impart a degree of plasticity or toughness to the steel to alleviate the brittleness of its martensite.

Tensile Strength (Test)

(Also called Ultimate Strength) - Breaking strength of a material when subjected to a tensile (stretching) force. Usually measured by placing a standard test piece in the jaws of a tensile machine, gradually separating the jaws, and measuring the stretching force necessary to break the test piece. Tensile strength is commonly expressed as pounds (or tons) per square inch of original cross section.

Ternary Alloy

An alloy that contains three principal elements.

Terne

Sheet steel coated with a mixture of lead and tin. Terne principally is used in the manufacture of gasoline tanks, although it also can be found in chemical containers, oil filters and television chassis.

Terne Plate

Sheet steel, coated with a lead-tin alloy. The percentage of tin is usually kept as low as possible because of its high cost; However, about 15% is normally necessary in order to obtain proper coating of the steel, since pure lead does not alloy with iron and some surface alloying is necessary for proper adhesion.

Thermal Analysis

A method of studying transformations in metal by measuring the temperatures at which thermal arrests occur.

Thermocouple

A device for measuring temperatures by the use of two dissimilar metals in contact; the junction of these metals gives rise to a measurable electrical potential with changes in temperature.

Thickness Gage or Feeler Stock

A hardened and tempered, edged, ground, and polished thin section, high carbon strip steel. Usually 1/2 in width and in thicknesses from .001 to .050 manufactured to extremely close tolerances. It is used primarily for determining measurement of openings by tool and die makers, machinists, and automobile technicians. It is prepared in handy pocket size knife-like holders containing an assembly of various thicknesses. Also prepared in standard 12 lengths with rounded ends and in 10 ' and 25' coils. Universally used in the metal industry.

Three-Quarter Hard Temper

(A) In stainless steel strip tempers are based on a minimum tensile or yield strength. For Chromium-Nickel grades three-quarter hard temper is 175,000 T.S., 135,000 Y.S. min. (B) In Brass mill terminology, this temper is three B&S numbers hard or 29.4% thickness reduction.

Tin

Chemical symbol Sn. Element No. 50 of the periodic system; atomic weight 118.70. Soft silvery white metal of high malleability and ductility, but low tensile strength; melting point 449 (degrees) F., boiling point 4384 (degrees) F., yielding the longest molten-state range for any common metal; specific gravity 7.28. Principal use as a coating on steel in tin plate; also as a constituent in alloys.

Tin Mill

Continuous tin-plating facility to produce tin mill steel sheet to be used in food and beverage cans and other containers.

Tin Plate

Thin sheet steel with a very thin coating of metallic tin. Tin plate is used primarily in canmaking.

Tin Plate Base Box

A Tin Plate Base Box is measured in terms of pounds per Base Box (112 sheets 14 x 20) a unit peculiar to the tin industry. This corresponds to it's area of sheet totaling to 31.360 square inches of any gage and is applied to tin plate weighing from 55 to 275 pounds per base box. To convert to decimal thickness multiply weight per base box by .00011.

Tin Plating

Electroplating metal objects with tin; the object to be coated is made cathode (negative electrode) in an electrolytic bath containing a decomposable tin salt.

Tin/Chrome Plating

A plating process whereby the molecules from the positively charged tin or chromium anode attach to the negatively charged sheet steel. The thickness of the coating is readily controlled through regulation of the voltage and speed of the sheet through the plating area.

Tin-Free Steel

Chromium-coated steel. Because it is used in food cans just like tin plate, it ironically is classified as a tin mill product. Tin-free steel is easier to recycle because tin will contaminate scrap steel in even small concentrations.

Tinning

Coating with tin, commonly either by immersion into molten tin or by electro-deposition; also by spraying.

Titanium

Chemical symbol Ti. Element No. 22 of the periodic system; atomic weight 47.90; melting point about 3270 (degrees) F.; boiling point over 5430 (degrees) F.; specific gravity 4.5. Bright white metal, very malleable and ductile when exceedingly pure. Its principal functions as an alloy in the making of steel. (1) Fixes carbon in inert particles (a) reduces martensitic hardness and hardnability in medium chromium steels. (b) prevents formation of austenite in high-chromium steels. (c) prevents localized depletion of chromium in stainless steel during long heating. Now finding application in its own right because of its high strength and good corrosion resistance.

Tolerances

A customer's specifications can refer to dimensions or to the chemical properties of steel ordered. The tolerance measures the allowable difference in product specifications between What a customer orders and What the steel company delivers. There is no standard tolerance because each customer maintains its own variance objective. Tolerances are given as the specification, plus or minus an error factor; the smaller the range, the higher the cost.

Tolerance Limit

The permissible deviation from the desired value.

Toll Processing

The act of processing steel for a fee ("toll"). Owners of the steel sheet may not possess the facilities to perform needed operations on the material (or may not have the open capacity). Therefore, another steel mill or service center will slit, roll, coat, anneal, or plate the metal for a fee.

Ton

Unit of measure for steel scrap and iron ore.
GROSS TON 2,240 pounds.
LONG (NET) TON 2,240 pounds.
SHORT (NET) TON 2,000 pounds. Normal unit of statistical raw material input and steel output in the United States.
METRIC TON 1,000 kilograms. 2,204.6 pounds or 1.102 short tons.

Tool Steels

Steels that are hardened for the use in the manufacture of tools and dies.

Trace

Extremely small quantity of an element, usually too small to determine quantitatively

Trade Case

A type of lawsuit filed by United States companies against their foreign counterparts in response to imports at prices lower than those in the U.S. market. Sanctions can be imposed by the International Trade Commission and the Commerce Department on foreign producers involved in dumping and government subsidization, if domestic manufacturers can prove material damage to their results.

Transformation

A constitutional change in a solid metal, e.g., the change from gamma to alpha iron, or the formation of pearlite from austenite.

Transformation Ranges (Transformation Temperature Ranges)

Those ranges of temperature within which austenite forms during heating and transforms during cooling. The two ranges are distinct, sometimes overlapping but never coinciding. The limiting temperatures of the ranges depend on the composition of the alloy and on the rate of change of temperature, particularly during cooling.

Transformation Temperature

The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range. The following symbols are used for iron and steels: . Ac(cm) In hypereutectoid steel, the temperature at which the solution of cementite in austentite is completed during heating. . Ac1 The temperature at which austenite begins to form during heating. . Ac3 The temperature at which transformation of ferrite to austenite is completed during heating. . Ac4 The temperature at which austenite transforms to delta ferrite during heating. . Ae(cm) Ae1 Ae3 Ae4 The temperatures of phase changes at equilibrium. . Ar(cm) In hypereutectoid steel, the temperature at which precipitation of cementite starts during cooling. . Ar1 The temperature at which transformation of austenite to ferrite or to ferrite plus cementite is completed during cooling. . Ar3 The temperature at which austenite begins to transform to ferrite during cooling. . Ar4 The temperature at which delta ferrite transforms to austentie during cooling. . M(s) (or Ar) The temperature at which transformation of austenite to martensite starts during cooling. . M(f) The temperature at which martensite formation finishes during cooling. . NOTE: All these changes except the formation of martensite occur at lower temperatures during cooling than during heating, and depend on the rate of change of temperature.

Transition Temperature

(1) An arbitrarily defined temperature within the temperature range in which metal fracture characteristics determined usually by notched tests are changing rapidly such as from primarily fibrous (shear) to promarily crystalline (cleavage) fracture. Commonly used definitions are transition temperature for 50% cleavage fracture, 10-ft-lb transition temperature, and transition temperature for half maximum energy. (2) Sometimes also used to denote the arbitrarily defined temperature in a range in which the ductility changes rapidly with temperature.

Transition Temperature (ductile-brittle transition temperature)

An arbitrarily defined temperature that lies within the temperature range in which metal fracture characteristics (as usually determined by tests of notched specimens) change rapidly, such as from primarily fibrous (shear) to primarily cleavage.

Troosite (obsolete)

A previously unresolvable rapidly etching fine aggregate of carbide and ferrite produced either by tempering martensite at low temperature or by quenching a steel at a rate slower than the critical cooling rate. Preferred terminology for the first product is tempered martensite; for the latter, fine pearlite.

Trowel Steel

Hardened and tempered spring steel. .90 to 1.05 carbon content. Ordinary tolerances, but rolled extra flat -- Rockwell C 50. Used in the manufacture of plastering trowels.

Truss Spring Steel

Supplied cold rolled and bright annealed. Carbon content about .70 -- Manganese .74. Must be formed very severely and must be as free as possible from decarburization.

Tubing

When referring to OCTG, tubing is a separate pipe used within the casing to conduct the oil or gas to the surface. Depending on conditions and well life, tubing may have to be replaced during the operational life of a well.

Tukon Hardness (Test)

A method for determining micro-hardness by using a Knoop diamond indenter or Vickers square-base pyramid indenter.

Tumbling

Cleaning articles by rotating them in a cylinder with cleaning materials.

Tundish

The shallow refractory-lined basin on top of the continuous caster. It receives the liquid steel from the ladle, prior to the cast, allowing the operator to precisely regulate the flow of metal into the mold.

Tungsten

Chemical symbol W. Element No. 74 of the periodic system; atomic weight 183.92. Gray metal of high tensile strength, ductile and malleable when specially handled. It is immune to atmospheric influences and most acids, but not to strong alkalis. The metal is used as filament and in thin sheet form in incandescent bulbs and radio tubes. (1) Forms hard abrasion -- resistant particles in tool steels. (2) Promotes hardness and strength at elevated temperatures.

Tungsten Carbide

Compound of tungsten and carbon, of composition varying between WC and W2C; imbedded in matrix of soft metal, such as cobalt, extensively used for Sintered Carbide Tools.

Tunnel Furnace

Type of furnace whereby stock to be heated is placed upon cars which are then pushed or pulled slowly through the furnace.

Twist

A winding departure from flatness.

Two-Coat System

The combination of a prime coat and a finish coat into a specified paint film. A typical 1 mil, two-coat system will have about 0.2 mil of primer coat and about 0.8 mil of finish coat.

Back to Top

Ultimate Strength

The maximum conventional stress, tensile, compressive, or shear, that a material can withstand.

Ultrasonic Frequency

A frequency, associated with elastic waves, that is greater than the highest audible frequency, generally regarded as being higher than 15 kc per sec.

Universal Mill

A rolling mill in which rolls with a vertical axis roll the edges of the metal stock between some of the passes through the horizontal rolls.

Upsetting

1) A metal working operation similar to forging.
2) The process of axial flow under axial compression of metal, as in forming heads on rivets by flattening the end of wire.

Utility Sheet Aluminum

Mill finish coiled or flat sheet of unspecified composition and properties produced in specific standard sizes and suitable for general building trade usage.

Back to Top

Vacuum Degassing

An advanced steel refining facility that removes oxygen, hydrogen and nitrogen under low pressures (in a vacuum) to produce ultra-low-carbon steel for demanding electrical and automotive applications. Normally performed in the ladle, the removal of dissolved gases results in cleaner, higher-quality, more pure steel (see Ladle Metallurgy).

Vacuum Oxygen Decarburization (VOD)

WHAT Process for further refinement of stainless steel through reduction of carbon content.
WHY The amount of carbon in stainless steel must be lower than that in carbon steel or lower alloy steel (i.e., steel with alloying element content below 5%). While electric arc furnaces (EAF) are the conventional means of melting and refining stainless steel, VOD is an economical supplement, as operating time is reduced and temperatures are lower than in EAF steelmaking. Additionally, using VOD for refining stainless steel increases the availability of the EAF for melting purposes.
HOW Molten, unrefined steel is transferred from the EAF into a separate vessel, where it is heated and stirred by an electrical current while oxygen enters from the top of the vessel. Substantial quantities of undesirable gases escape from the steel and are drawn off by a vacuum pump. Alloys and other additives are then mixed in to refine the molten steel further.

Vanadium

Chemical symbol V. Element No. 23 of the periodic system; atomic weight 50.95. Gray-white, hard metal, unaffected by atmospheric influences or alkalis but soluble in most strong acids; melting point 3119 (degrees) F.; boiling point about 6150 (degrees) F.; specific gravity 5.87. It cannot be electrodeposited. Its principal functions as an alloy in the making of tool steels. (1) Elevates coarsening temperature of austenite (promotes fine grain). (2) Increases hardenability (when dissolved) (3) Resists tempering and causes marked secondary hardening.

Virgin Metal

Metal obtained directly from ore and not used before.

Vibrated Wound

(See Oscillated Wound Coils)

Vibrator Reed Steel

Hardened, temper and white polished extra precision rolled. Carbon content about 1.00%. Steel must withstand great fatigue stresses.

Vickers Hardness (Test)

Standard method for measuring the hardness of metals, particularly those with extremely hard surfaces: the surface is subjected to a standard pressure for a standard length of time by means of a pyramid-shaped diamond. The diagonal of the resulting indention is measured under a microscope and the Vickers Hardness value read from a conversion table.

Voluntary Restraint Agreements (VRAs)

A compromise reached between the U.S. government and foreign steel-exporting nations. Instead of the United States imposing punitive duties on subsidized steel imports, the foreigners would "voluntarily" limit their steel exports to the United States.

Back to Top

Walking Beam Furnace

A type of continuous reheat furnace in which the billet or slab moves through distinct heating zones within the furnace: By controlling the speed through the zones, steelmakers can achieve precise rolling temperatures and consume less fuel during operation.

Wash Coat

A very thin paint film applied to the back side of a prepainted sheet specified to have one finished side. The wash coat provides protection in coiling , storage, fabricating and handling.

Wasters

Sheets that have prohibited defects, for example seams and buckled plates. Generally fit for re-melting purposes only.

Watch Main Spring Steel

Usually supplied cold rolled and annealed in large widths and cut and hardened by the spring manufacturers. Carbon content about 1.15% and Tungsten .17%, extra precision rolled.

Water Hardening

Process of hardening high carbon steels by quenching in water or brine after heating.

Wavy

Not flat. A slight wave following the direction of rolling and beyond the standard limitation for flatness.

Weathering Steel

A steel using alloying elements such as copper, chromium, silicon and nickel to enhance resistance to atmospheric corrosion. (USS COR-TEN®)

Wedge

A hardwood stick used as a forming tool in spinning.

Welding

A process used to join metals by the application of heat. Fusion welding, which includes gas, arc, and resistance welding, requires that the parent metals be melted. This distinguishes fusion welding from brazing. In pressure welding joining is accomplished by the use of heat and pressure without melting. The parts that are being welded are pressed together and heated simultaneously, so that recrystalization occurs across the interface.

Wet Film Thickness

The thickness of the paint film immediately after coating and prior to curing. The required wet film thickness is dependent on the proportion of solids and solvents in the liquid paint for producing the appropriate dry film thickness.

Wide-Flange Beam

A structural steel section on which the flanges are not tapered, but have equal thickness from the tip to the web and are at right angles to the web. Wide-flange beams are differentiated by the width of the web, which can range from 3 inches to more than 40 inches, and by the weight of the beam, measured in pounds per foot.

Widths

The lateral dimension of rolled steel, as opposed to the length or the gauge (thickness). If width of the steel strip is not controlled during rolling, the edges must be trimmed.

WMB, WHB and Extra WHB Grades

Spring steel wires produced from acid open-hearth steels (see M B Grade).

Work Hardenging

Increase in resistant to deformation (i.e. in hardness) produced by cold working.

Workability

The characteristic or group of characteristic that determines the ease of forming a metal into desired shapes.

Worms

(See Stretcher Strains)

Wrought Iron

Iron containing only a very small amount of other elements, but containing 1-3% by weight of slag in the form of particles elongated in one direction, giving the iron a characteristic grain. Is more rust-resistant than steel and welds more easily.

Back to Top

X-Rays

Light rays, excited usually by the impact of cathode rays on matter, which have wave lengths between about 10-6 cm, and 10-9 cm; also written X-rays, same as Roentgen rays.

Back to Top

Yellow Brass

65% copper and 35% zinc. Also known as High Brass. A copper-zinc alloy, named for its yellow hue. Formerly a very popular alloy, but now largely replaced by Cartridge Brass.

Yield

The ratio of the quantity of finished shipments to the total raw steel produced, adjusted for changes in inventory and any slabs that are purchased from outside. Yield has significantly improved during the past decade, primarily as the result of the industry's conversion to continually cast steel, whose yield is superior to that of traditional ingot teeming.

Yield Point

The load per unit of original cross section at which, in soft steel, a marked increase in deformation occurs without increase in load.

Yield Strength (YS)

The stress at which a material exhibits a specified limiting deviation from the proportionality of stress to strain. The deviation is expressed in terms of strain. Also known as proof stress.

Young's Modulus

The coefficient of elasticity of stretching. For a stretched wire, Young's Modulus is the ratio of the stretching force per unit cross-sectional area to the elongation per unit length. The values of Young's Modulus for metals are of the order 10(12) dynes per square cm.

Back to Top

Zinc

(Chemical Symbol Zn.) - Element No. 30 of the periodic system; atomic weight 65.38. Blue-white metal; when pure, malleable and ductile even at ordinary temperatures; melting point 787 (degrees) F.; boiling point 1665 (degrees) F., specific gravity 7.14. Can be electrodeposited; it is extensively used as a coating for steel and sheet zinc finds many outlets, such as dry batteries, etc. Zinc-base alloys are of great importance in die casting. Its most important alloy is brass.

Zirconium

(Chemical Symbol Zr.) - Element No. 40 of the periodic system. Atomic weight 91.22. Specific gravity 6.5 and melting point at about 3200° +/- 1300°F. Because of its great affinity for oxygen and combines readily with nitrogen and sulfur, it is used as a deoxidizer and scavenger in steel making. It is used as an alloy with nickel for cutting tools and is used in copper alloys.