Glossary of terms


Aging (age hardening):
Changes in physical and mechanical properties that occur when low carbon steel is stored for some time (steel becomes “harder” and less ductile). Aging is accelerated by exposure of the steel to elevated temperatures.

American Iron and Steel Institute (AISI):
A Washington, D.C.-based steel association serving as the voice of the American steel industry in the public policy arena.

A partial or complete solid solution of one or more elements in a metallic matrix.

Cold-rolled substrate with aluminum coating applied using the hot-dipped process. Steel has excellent heat resistance and is used in burner tube applications (furnaces), automotive mufflers and other applications were heat is a major consideration.

A process involving high-temperature heating and cooling of cold-rolled steel substrate to make it softer and more formable.

Annealing Stain:
A discoloration on annealed material which may occur anywhere on the sheet, resulting from residue or oxidation during annealing.

American Society for Testing and Materials. A non-profit organization which provides a forum for producers, users, ultimate consumers, and those having general interest (representatives of government and academia) to meet on common ground and write standards for materials, products, systems and services. ASTM standards are used to set the basic standards which define the requirements and procedures governing steel products. ASTM provides a numbering system as a reference point used throughout the industry (example: ASTM A653 which covers sheet steel produced by the hot-dipped galvanizing process).

Backer coat:
Usually refers to the coating on the reverse side of a prepainted sheet.

Bake hardenable steel:
Steel sheet which is aluminum killed and are resistant to room temperature age hardening. The steel offers good formability. During the forming operation the steel gains yield strength and offers greater resistance to dents or dings. This steel is primarily used in automotive exposed applications.

The basic form of hot rolled coil prior to undergoing skin-passing or other post primary rolling operations. Hot rolled coil commonly referred to as “hot bands”.

Band mark:
An indentation caused by the packaging band resulting from external pressure on coils/ cut lengths that may occur in handling, transit and storage.

Base steel thickness:
The thickness of sheet steel without any coatings.

Basic oxygen furnace (BOF):
A facility to produce steel by the metallurgical process of oxygen injection into a mixture of molten iron and scrap. Associated with the BOF are iron and steel desulfurization, argon stirring, alloy trimming, steel reheating and vacuum degassing.

Bend radius:
The inside radius of a bent section of steel, normally indicated as a factor of material thickness or “T”. A 1-T bend diameter = 1/2-T bend radius.

Bend test:
Tests used to determine steel ductility during which steel is bent either with or against the grain.

Black plate:
Very light-gauge cold-rolled substrate which is used as feedstock for Tinplate or can also be run through the hot-dipped galvanized process to produce ultralight-gauge galvanized steel.

A processed steel sheet with highly restrictive width, length and diagonal tolerances.

A small raised area on the surface resulting from the expansion of subsurface inclusions.

Specially pretreated hot-dipped galvanized where relatively thick or dense crystalline deposit of hydrated zinc-phosphate compounds is applied to the galvanized surface. This is done at the end of the galvanizing line at the producing mill. The result is a dull gray appearance which provides an excellent surface for paint to be applied by various forms of application. Bonderized is also referred to as Phosphatized.

Batch (box) annealing:
Full hard (tandem rolled) coils are softened by heating in a closed container through which a protective atmosphere circulates to prevent oxidation.

Chemical symbol B – Boron is an additive to base metal during the melt process which is used to improve ductility and hardenability.

Breaks (cross breaks):
Creases or ridges that may occur in untempered or in aged material. Depending on the origin of the break, it might be termed a cross break, a coil break, or an edge break.

A series of waves in sheets which are ordinarily transverse to the direction of rolling.

The ridge left on the edge of steel after it has been slit, sheared, blanked or sawed.

The deviation of a side edge from a straight line, the measurement being taken on the concave side with a straight edge.

Main hardening element in steel with the chemical symbol C.

Carbon steel:
Steel containing carbon up to about 2% and only residual quantities of other elements except those added for deoxidization, with silicon limited to 0.60% and manganese to about 1.65%.

Center buckle:
A condition in a sheet steel where the center of the steel (in the rolling direction) is longer than the edges and has a wave or buckle.

A series of lines uniformly spaced appearing transverse to the rolling direction, resulting in a very slight thickness variation where lines appear.

Chemical treatment:
A solution of corrosion-inhibiting chemicals applied to the surface of coated steel sheet (such as galvanized steel). For many years chromate was the chemical of choice. Currently non-chrome or RoHS compliant chemicals are available which do not contain chrome. When steel has been treated with chemicals to inhibit rust the steel is referred to as chemically treated and is either dry – CTD – (no oil) or oiled – CTO or CTLO – (a prelube or other oil is on the surface of the steel).

A chemical element with the symbol Cr. Chromium is used to inhibit rust. It is also used to harden steel. Chromium is prominent in stainless steel.

Coil breaks:
Creases or ridges in sheet that appear as parallel lines across the direction of rolling, and that generally extend the full width of the sheet or strip.

Coating thickness:
The thickness of steel sheet including any metallic coatings (i.e. zinc or 55% aluminum-zinc alloy) and paint coatings.

Coating weight:
The thickness of the zinc and or aluminum applied to the base substrate (hot rolled or cold rolled) in galvanized, electro-galvanized, aluminized and Galvalume sheet steel. In the US the thickness can be measured in ounces per square foot or grams per square meter. Ounces are the measurement used in most applications where automotive uses grams per square meter in their applications.

Cold-rolled steel:
Flat-rolled steel products for which the final required thickness has been obtained by rolling base hot-rolled pickled substrate at room temperature. This is accomplished by passing the steel through work rolls under tremendous pressure which tightens thickness tolerances, improves shape and surface quality. The initial product coming through the work rolls is called cold-rolled full-hard and from there the coils will need to be annealed in order to become fully processed cold-rolled steel.

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. A complete color standard definition will usually include painted panels representative of the limits of acceptable deviation from the precise standard color as well.

A chemical element with the symbol Cb. Columbium is often used in high-strength, low alloy steels to increase yield and tensile strength.  Note: Columbium (Cb) is the old name and the new name is niobium (Nb).

Commercial quality (CQ):
A quality of steel sheet which can simply bent or undergo moderate forming. Commercial quality steel can be bent upon itself flat in any direction at room temperature without fracturing. Commercial quality or CQ is no longer used by the majority of the steel industry. The proper term is commercial steel (CS).

Commercial steel (CS):
Steel intended for simple bending or moderate forming applications where the steel can be bent upon itself flat in any direction at room temperature without fracturing. You will see the designation CS, CS/A or CS/B within the industry.

Continuous casting:
Ability to convert molten steel directly into slabs eliminating the traditional steps of first producing ingots (molds) and from there producing slabs. Most (if not all) US mills now continuous cast their slabs.

Continuous heat treating (continuous annealing):
A full hard coil is uncoiled and fed into a line containing a series of furnaces, cooled and then recoiled at the delivery end of the line. Each part of the coil is thus heated rapidly up to temperature and cooled down quickly, all under protective atmosphere to prevent oxidation.

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

Chemical element with the symbol Cu. Copper is used to help reduce atmospheric corrosion resistance.

(aka rust) Gradual chemical or electro-chemical attack on a metal by atmospheric moisture or other agents. Corrosion causes pitting of the surface of the base metal if allowed to continue over time.

The contour of sheet steel where the thickness of the steel increases from the edge of the strip to the center. A crown is needed to produce galvanized steel to help remove excess molten zinc from the surface of the steel. Normal galvanizing lines require a 3% thickness variance from the edge of the strip to the center.

Commercial steel type B which is the standard specification for mild carbon steel.

Cut edge:
Edge of a hot rolled coil or hot band which is more defined and has tighter tolerances than a mill edge (open tolerances) coil. The process removes the hot mill edge. Coil ends will be cropped back to gauge when steel is ordered with a cut edge.

Hundred weight or 100 pounds. Standard method of referencing pricing in the US. There are 20 hundred weights in one short ton and 22.0462 in a metric ton.

Process where the sharp edges (or burr) are removed or reduced from the edge of a slit or cut edge of sheet steel.

Deep drawing steel (DDS):
The process of forming steel using dies in a press where flat steel is formed into cup shapes or cup-like characteristics. Deep drawn steels are usually vacuum-degassed killed steels with high ductility. An example of a deep-drawn part is an oil filter.

The mass per unit volume of a substance. The mass of carbon steel is 0.2833 pounds per cubic inch or 40.8 pounds for 1” thickness X 12” X 12”. These unit measurements are important to use when calculating steel coil or sheet weights in the absence of a certified scale.

An imperfection resulting from foreign matter being mechanically pressed into the sheet surface.

Accidental impact damage, similar in appearance to dimples.

The shaping of a flat blank into a desired contour by causing the metal to flow over a draw ring and around a punch.

Drawing quality (DQ):
Terminology no longer used by the majority of the steel industry – see drawing steel (DS).

Drawing steel (DS):
For applications were greater formability is needed which cannot be achieved by forming steel (FS). Drawing steels have a higher degree of ductility and are more consistent performers than forming steel (FS) or commercial steel (CS) due to higher standards in the production, selection and melting of the base substrate.

High-strength steel strengthened by a bonded two phase microstructure composed of ferrite and martensite.

The ability to permit change of shape without fracture. In flat-rolled steel, ductility is usually measured by hardness or mechanical properties using a tensile test.

Dry film thickness:
The thickness of the dry paint film on the surface of the steel.

The process of accomplishing a particular shape to the edge of a strip or slit edge (i.e. round or square edge).

The ability of sheet steel to return to its original shape and dimensions.

Elastic ratio:
The yield point divided by the tensile strength.

Electro-galvanized sheet steel has a thin coating of zinc applied to the surface of the steel using an electric current and a electrolyte solution in a plating cell. Consumable zinc anodes are positioned close to the steel in the plating cells to maintain the required zinc content of the plating solution. Electro galvanized is used in some automotive applications to help inhibit rust and provide a superior product than bare cold rolled substrate.

A measurement of ductility/formability expressed by the increase by percentage (%) of a given distance (usually 2”) prior to a fracture occurring during a tensile test.

Embossed sheet:
A sheet having a prominent, impressed texture or pattern on its surface(s). If the defined texture is applied to one surface only, it is most properly termed a coined surface.

Entry mark (exit mark):
A slight corrugation caused by the entry or exit rolls or a roller leveling unit.

Extra smooth (XS):
A more uniform appear or finish imparted to galvanized or Galvalume steel by temper rolling (crushing the spangle through the use of works rolls under tremendous force) after the substrate has been coated. Temper rolling also imparts resistance to stretcher strain. Most extra smooth is for prepaint applications where surface appearance is critical.

Ferrous scrap:
Iron-containing used steel which is remelted and recast into new steel by both fully integrated mills (approximately 25% mix of scrap) and mini-mills (as much as100% mix of scrap).

One of the phases or microstructure constituents of steel at room temperature.

Finish coat:
The top coat or exposed prime side paint film.

A measurement of a cut length sheet’s ability to conform to a flat horizontal surface. The deviation is measured from the horizontal surface to the peak (or highest point) of the sheet which is not resting on the horizontal surface. For more information also see “I-Units.”

Flex rolling:
Passing sheets through a flex roll unit to minimize yield point elongation so as to reduce the tendency for stretcher strains to appear in forming.

Visible line markings that sometimes appear on the surface of flat-rolled steel during forming; associated with non-uniform yielding of the metal; occurs when steel is formed into cylindrical or arc shaped parts. Fluting (creases in the formed steel) can be avoided by working the steel (temper rolling) before bending.

The shaping of sheet metal by bending, uniaxial stretching, biaxial stretching, compression or by a combination thereof.

Forming steel (FS):
Softer or more ductile than commercial steel. Forming steel was formerly called lock-forming quality steel (LFQ) although most domestic and foreign mills produce their commercial steels so they can go through a lock seam application.

A break in the steel at the surface which can be seen either with the naked eye or under a microscope. Most fractures occur when sheet steel is bent or formed in some fashion.

Full hard (FH):
Sheet steel rolled without subsequent annealing. Generally Rockwell readings are higher than Rb80 with elevated yield and tensile strengths and very low elongation. Full hard cold-rolled steels (FHCR) are generally the base substrate used in hot-dipped galvanizing lines where the substrate is annealed in-line just prior to the zinc application process.

See gauge.

Galvalume (GLM or AZ):
Sheet steel is coated with aluminum-zinc alloy using the continuous hot-dipped process similar to the process used to make galvanized steel. The nominal coating composition is 55% aluminum and 45% zinc. Galvalume has superior corrosion resistance which is achieved by the intricate microscopic formation of zinc-rich and aluminum-rich zones within the coating. The aluminum provides long-term durability and zinc the corrosion protection. Galvalume is a registered trademark of BIEC International and you will find it under other names when produced by non-BIEC production facilities.

Galvanized (GI or GALV):
Carbon steel substrate – either cold rolled or hot rolled pickled (normally dry) – which has zinc applied to both sides. The zinc is applied as the substrate passes through a molten zinc bath and then is quickly dried. The process results in a layer of zinc tightly adhering to the base steel through an iron-zinc bonding layer. Zinc is applied to the steel for applications where corrosion resistance is important.

Galvannealed (GN or GA):
Carbon steel substrate which goes through the hot-dipped galvanized process. Immediately after exiting the molten zinc bath the strip enters a heat zone (Galvannealed rig) which converts the entire coating to a zinc-alloy layer. Galvannealed is usually gray in color and the surface is exceptional for post-paint applications (Chrysler and a number of foreign car manufacturers use it for the automotive skins).

A numbering system used to determine thickness and allowable range of flat rolled steel products. Most mills and large manufacturers no longer use gauge but prefer to specify the exact thickness required either by minimum (min.) which has a -0 plus thickness tolerances or, nominal (nom.) which have plus/minus thickness tolerances.

Gas jet cooling:
High pressure streams of an ambient temperature, non-oxidizing gas are directed against the hot strip to cool it to a desired temperature as it passes through the gas jet cooling zone of a continuous annealing line.

The property of a surface related to its ability to reflect light.

Gross ton (GT):
Measure of mass (weight). One gross ton weighs 2,240 pounds. We find scrap prices are based on gross tons.

Resistance of steel to surface penetration as measured by a Rockwell hardness tester. US customers are used to seeing the surface hardness measured on the “b” scale as in Rb 65 max for commercial steels.

Healed over scratch:
A scratch that occurred in an earlier mill operation and was partially masked in subsequent rolling.

The amount of steel produced out of a single melt at the producing mill.

Heat number:
The reference number used by the producing mill to keep track of steel originating from a specific melt. The heat number stays with the coil throughout the processing cycle unless it is designated as secondary (distressed) steel.

High carbon:
Steel with carbon content exceeding 0.30%. The more carbon in the steel the harder the product and less formable it becomes. High carbon steels are used in such products as shovels or plow blades.

High-strength steels (HSS):
Sheet steel calling for higher strength levels – usually customers order high-strength low-alloy (HSLA) in this category. HSLA sheet steel has higher strength through the addition of alloying elements such as columbium, vanadium and titanium used alone or in combination.

Hot-briquetted iron (HBI):
Direct-reduced iron which has been processed into a compact brick-shaped mass or briquette. Instead of using a blast furnace, the oxygen is removed from the ore using natural gas, which results in a substance that is 90-92% iron.

Hot end (of a mill):
The section of the mill between the furnace and up to the hot roll mill.

Hot metal:
Name for the molten iron produces in a blast furnace. From there it proceeds to the basic oxygen furnace (BOF) or is cast as pig iron.

Hot-rolled steel (HR, HRS, or HRC):
Flat-rolled steel produced from slab which is put through the mill work rolls to determine the final thickness while at high temperatures.

Hot strip mill:
A rolling mill that has several stands of rolls that convert slabs to hot-rolled coils. The rolls squeeze red-hot slabs, thus reducing the thickness and, at the same time, governing the width through the use of horizontal rolls. A hot mill can convert a slab up to 10 inches thick down to .250” with a length close to a quarter mile long.

HSLA (high-strength low-alloy):
One category of high-strength steel, necessarily containing certain strengthening elements such as columbium (Cb), vanadium (V), titanium (Ti) or others either singly or in combination.  Columbium has been replaced with Niobium (Nb).

The process of taking a tube and putting it into a forming die. The tube is then shaped to the form of the die by using internal water pressure. This is a process which is being used by the automotive industry for body rails, radiator supports and engine cradles.

I.D. (ID):
Inside diameter of a coil. Normal IDs in North America are: 16” (using tin mill/black plate products), 20”, 24”and 30”.

Impact testing:
Procedure to determine the resistance of steel to fracture under extreme conditions.

Non-metallic materials (such as oxides, sulfides or silicates) in steel as cast.

Semi-finished steel product which is accomplished by pouring molten iron into a mold and slowly letting it solidify. Ingots were then moved around the mill, the molds removed at the stripper building and then reheated and rolled into slabs.

Integrated steel mills:
Those steelmaking facilities which process iron ore into molten iron using blast furnaces. The hot end (blast furnaces, BOF, etc.) is the only difference between an integrated mill and a minimill. Virtually all of the integrated mills are involved in the production of flat-rolled steels – plate, hot-rolled, cold-rolled, coated steels (galvanized, Galvalume, aluminized, electro-galvanized), and tin mill products.

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

Intermediate temper:
Cold-rolled substrate with a hardness referenced within a 15-point Rockwell range. For example – Quarter Hard Rb 60-75.

Interstitial free (IF) steel:
Ultralow carbon steel – usually near or below 0.002 Carbon – produced using vacuum-degassing. IF steels are extremely ductile and are used primarily in automotive applications where there is a need for extra deep drawing or special forming.

Chemical symbol Fe – the largest part of carbon steel representing approximately 94.5% in the pure molten state.

Iron carbide:
One of the substitutes used in place of scrap in electric-arc furnaces (EAFs or minimills). Iron carbide producers use natural gas to reduce iron ore to iron carbide.

The unit of measure flatness is the “I” unit. One I-unit is a measure of the amount of elongation gaugation against the shortest measured segment and is measured as a 1/100000th part. One I-unit is defined as the flatness error caused by differential length (of different fibers of strip) of 0.001% or one part in 100,000. For more information also see “Flatness.”

Institute for Supply Management (ISM):
Organization of purchasing managers. It conducts a poll of its membership once per month, which results in the ISM Purchasing Managers Manufacturing Index (PMI), released on the first business day of each month and is a key economic indicator for those involved in the steel business.

Jet cooler:
Devices that controls the cooling of the steel strip before it enters the galvanizing pot.

Projecting part of crane from which lifting chain or gear is suspended.

Jumbo coil:
A single coil produced by welding two or more coils together.

Killed steel:
Steel deoxidized by silicon or aluminum to reduce the oxygen content in molten steel to a minimum prior to solidification of the metal. Killed steels have more uniform properties and chemical composition than other types of steels.

A vessel or “bucket” lined with refractory bricks used to transport molten steel in a steel mill.

Lamination or slivers:
Imperfections aligned parallel to the surface of the sheet resulting from the presence of inclusions.

Chemical symbol Pb – used in molten zinc baths (pots) in a hot-dipped galvanizing line in order to produce a large spangle. Most North America mills have removed lead from their pots and are using antimony as a replacement or have gone “spangle free.”

Lead time:
The amount of time from the placement of an order until it is ready for delivery.

The process of removing coil set and flattening or correcting the shape of the steel by putting the steel through a series of rolls under a tremendous amount of force.

Light-gauge steel:
Cold-rolled substrate which is lighter than .018” in thickness. This has become a very generalized term for all thin steels which would include tin plate as well as galvanized and other coated steels under .018” in thickness.

Light matte finish:
Cold rolled surface which has a profilometer range of 20-40 micro-inches. The intention is for a smooth surface for painting such as metal furniture applications.

Lockforming quality (LFQ):
An old term used to determine if galvanized steel could be put through a piece of machinery called a lockformer – which usually takes the steel and performs back-to-back 180 degree bends. The result is having the steel lock itself together much like taking your fingers curling them and gripping both hands together. The LFQ designation is no longer being used. Instead we use either CS/B or FS to describe the product needed to make a lockseam application (normally HVAC ductwork).

London Metal Exchange (LME):
The metals trading center for the Western world. The LME determines precious metal futures pricing for zinc, aluminum, copper, etc. many of which are used in the steelmaking process.

Long products:
Classification of steel products which includes bar, rod, beams, and other structural pieces which are not rolled flat.

Low carbon steel:
Sheet steel substrate with a carbon content usually under 0.005%.

Lubricity slipperiness:
The ability of steel sheet to be able to slide in a forming die.

Lüders lines:
(Stretcher strain) Irregular surface markings or depressions caused by localized plastic deformation resulting from yield point elongation.

Chemical symbol Mn – moderately hard element used to strengthen or harden steel.

Man-hours-per-ton (M-H/Ton):
The ratio of total hours worked by steelworkers to the tons shipped during a given period of time.

One of the phases or microstructure constituents of steel at room temperature. Characterized by its high strength and hardness, it is the phase responsible for the high strength of dual phase steels.

Matte finish:
A gritty surface look on cold-rolled steel accomplished by roughened rolls during the cold rolling process.

Mechanical properties:
The structural qualities measured by tensile strength, elongation and yield strength in sheet steel.

Metric ton (MT):
A measure of mass (weight). One metric ton equals 2,204.62 pounds.

A piece of hand held equipment used to measure the thickness of the steel.

A term used to indicate thickness of 0.001″.

Mild carbon steel:
Sheet steel usually with a carbon content between 0.005-0.010.

Mill edge:
Standard edge off the hot mill with very liberal width and shape tolerances.

Minimum spangle (MS):
Very small flower (crystallization of the zinc) pattern on the surface of galvanized steel. There are no standards for specific flower size but generally refers to barely visible flower to no flower pattern at all.

Steel mills that utilize scrap steel (or scrap substitutes) to make new steel. The scrap is charged or heated by using electricity in an electric arch furnace (EAF). There are a number of minimills in the US with the best known being Nucor, Steel Dynamics Inc., Commercial Metals Co., Gerdau North America, Big River Steel. A number of the minimills produce long products as well as flat-rolled sheet steel.

Chemical symbol Mo – used in high-strength low-alloy grades to increase yield and tensile strength.

Based on current sales, the amount of time it will take to eliminate inventory current on a company’s floor.

Motor lamination/electrical steels:
A type of cold rolled used as electromagnetic core material for electrical equipment (motors, transformers, etc.). Cleveland-Cliffs is the major US producer of motor lamination or electrical steels. Big River Steel plans to start an electrical steel line in 2024.

Chemical symbol Nb – often used in high-strength low-alloy steels for increased yield and tensile strength.  Note: Columbium (Cb) was replaced by niobium (Nb).

No. 1 heavy melt scrap (HMS):
Obsolete steel scrap grade made up of pieces at least one-quarter inch in thickness in pieces no larger than two feet by five feet. Minimills are the primary consumers of HMS products.

OD (O.D.):
Outside diameter of a steel coil.

Terminology used when a piece of equipment is shut down and/or not operating.

Oil can:
An area in a formed panel that when depressed slightly will recover its original contour after the depressing force is removed.

Application of prelube or other oil to the surface of steel to either inhibit rust or assist in the lubricity of the steel as it moves through manufacturing dies.

Olsen test:
A piece of testing equipment used to measure ductility or the drawing qualities of sheet steel.

Operating rates:
The ratio between the raw steel production rates of a mill compared to its stated capacity. Also called capacity utilization rates.

The practice of winding coils so that the outside walls of the coil appear to be like waves (steel is wound in and out by moving the recoiler mandrel back and forth). In the extreme you can get a telescoping affect which is deemed a defect. On light gauge galvanizing lines it is used to help prevent galvanized build up on the edges which causes a belled or wavy edge on one side of the strip.

Segment of the continuous annealing process following the high temperature soak and quench period. The steel is reheated to intermediate temperatures and intentionally aged in line to make the steel more stable during subsequent room temperature storage.

The reaction between oxygen and steel over time which can cause pitting, stain, and the loss of strength.

Peak earnings:
The top of the business cycle when a company is able to maximize profits.

Fine particles of iron ore mixed with bonding clay and heated into round balls which are used to feed a blast furnace. Also called taconite pellets.

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.

Chemical treatment in a phosphate solution of metallic coated sheet to prepare the surface for painting.

Physical properties:
A general term that refers to any property of a material. For example: Density, electrical conductivity, thermal expansion, mechanical properties, etc.

Process of removing scale and rust from the surface of hot-rolled steel using hydrochloric acid baths. Usually after the pickling process is complete the steel is cleaned and then oiled to protect the steel from rusting quickly – this is called hot rolled pickled & oiled (HRPO). If the steel is going to a galvanizing facility it normally is produced dry (HRPD).

Pig iron:
Melted iron in a blast furnace containing a large amount of carbon (above 1.5%). The name comes from the time in history when molten iron was poured trenches and from there into shallow holes (or molds). From above the arrangement looked like baby pigs suckling. The central trench became known as the “sow” and the molds became known as “pigs.”

Fernlike ripples or creases usually diagonal to the rolling direction.

When pipe is encountered it will be: 1. Located at or near the center of the sheet width as rolled; 2. At the middle of the sheet thickness; 3. Of substantial width and length; and 4. Discolored on the plane of cleavage.

Small cavities in the surface of the sheet.

Sheet steel with a thickness of at least one-quarter of an inch (.250”) or more and a minimum width of eight inches.

Pounds per inch of width (PIW):
Calculated by taking coil actual scale weight and dividing by width in inches. An example: A 20,000 pound 60” wide coil is 333 PIW (pounds per inch of width). The larger the PIW of a coil the bigger the coil and the bigger the OD (outside diameter) of the coil.

Oil coating applied to sheet to enhance formability.

Primer Coat:
The base coat of paint in a typical two coat paint system.

Instrument used to measure surface roughness.

Pup coil:
A coil with less than 200 PIW (pounds per inch of width). Basically, it’s a light-weight coil.

A modified basic oxygen furnace which blows oxygen and other gases in from the bottom rather than the top. Current state-of-the-art furnaces allow for 60% of the gases to be blown in from the top and the remainder from the bottom of the vessel.

Qualification trials:
Before any new grade of steel is accepted for manufacture, it must go through the testing procedure to ensure it will make the part.

Refers to the suitability of the steel for the purpose or purposes for which it is intended.

Quarter hard:
In cold-rolled steel, a hardness range between Rb 60-75 which is suitable for limited bending and roll forming.

Very rapid cooling of the steel strip by means of water sprays and/or submerging in water.

Reducing agent:
Either natural gas or coal can be used to remove oxygen from iron ore to produce a scrap substitute. The oxygen in the iron ore combines with the carbon and hydrogen in the gas or coal producing a metallic iron.

Reel breaks (reel kinks):
Transverse breaks or ridges on successive inner laps or a coil which are the result of crimping the lead end of the coil into a gripping segmented mandrel.

Reflectivity (reflectance):
A term to indicate the percentage of reflected light from a painted surface.

Refractory brick:
Heat-resistant brick used to line the walls of a blast furnace, sides of ladles, and inside a basic oxygen furnace (BOF).

The process of replacing worn out refractory brick in a blast furnace, ladle, or BOF. Relines can take 45 days to three months to complete and are very expensive.

Are the impurities left as a result of the mix of steel scrap used by a minimills in an electric furnace operation. Impurities (high residuals) can leave steel too brittle for its intended use.

Reversing mill:
A stand of reducing rolls where steel strip is passed back and forth through the rolls reducing the thickness of the steel with each pass.

A test measurement to determine surface hardness. Surface hardness is measured on a “b” scale. Rb 50-65 is considered normal Rockwell for commercial sheet steel.

Fabrication method in which coiled steel is passed through rolls which progressively form the steel to a predetermined profile.

Roll leveler:
A series of small-diameter staggered rolls used primarily to improve flatness and/or to partially remove yield point elongation.

Roll leveler breaks:
Obvious transverse breaks usually 1/8” to ¼” apart caused by the sheet fluting during roller leveling. These will not be removed by stretching.

Roll leveler lines:
Lines running transverse to the direction of leveling. These may be seen upon stoning or light sanding after leveling and before drawing.

Roughing stand:
First stand of rolls through which hot metal passes during the hot rolling process. Once through the first stand of rolls the metal continues on to the finishing stands where smoother rolls reduce the coil to its final hot rolled thickness.

Sacrificial barrier:
A coating, such as zinc, which “sacrifices” itself to the corrosive elements of the atmosphere to protect the steel from corrosion (rusting or pitting).

Salt spray test:
A procedure where steel sheet is exposed to the corrosive effects of salt water. The purpose is to see how long the steel can withstand the exposure before breaking down.

Cutting metal (usually plate or heavy-gauge hot rolled) into customer requested width, lengths or shapes.

Marring or scratching of a formed part by metal pickup on the punch or die.

Scrap steel:
(See ferrous scrap)

Scrap substitute:
Raw materials which can be used in an EAF in place of scrap. They include pig iron, HBI, DRI, and iron carbide.

Lines caused by the abrasion of one surface against another during rolling, processing or shipping.

Secondary steel:
Steel that did not meet the original customer’s specifications because of a defect in chemistry, appearance, or other quality imperfections. If another prime customer cannot use the steel in its existing condition, it is often sold as a defective product at a reduced price in the marketplace.

The variation in chemical composition resulting from elements with the lowest freezing points concentrating in the last part of the ingot or slap to solidify.

Semi-finished steel:
For flat-rolled steel, this would mean slabs which can be reheated at a later time and rolled into sheet products. For long products, this can be blooms, billets, and ingots.

Service center:
A generic name for steel distributors which buy steel from mills (domestic and foreign) and resell the metal into the manufacturing sector (or to other distribution facilities). Service centers sell steel – not a manufactured product.

Shape correction:
The process of using levelers, temper mills, edge trimmers and other pieces of equipment to reprocess steel to meet a customers specifications.

Flat rolled steel usually less than .250 inches in thickness and wider than 12 inches. Sixty-five percent of the U.S. steel market is sheet steel (hot rolled, cold rolled, galvanized, Galvalume, aluminized and tin mill products).

Shredded scrap:
Baseball-sized pieces of old automobiles after being reduced by a shredder at the scrap yard. Magnets separate the reusable portion of the vehicle, which, once shredded, is sold to minimills to make new steel.

The contour of the sides of a steel coil. Prime mill steel sidewalls are generally smooth and free or damage. However, in light gauge steels the sidewalls can be intentionally oscillated to reduce the risk of buildup on the edges of the strip.

Steel which has passed through a temper mill (sometimes called extra smooth).

The beginning mass either produced by continuous casting or in an ingot mold. Slabs are then reheated and rolled into hot bands or hot-rolled coils.

Slit edge:
The edge of a coil or sheet after being fed through a highly tempered knives located on the slitter head. The edge of slit coils has tighter tolerances than normal mill run edges.

The continuous cutting of a master coil into narrower width strip(s).

Surface ruptures.

Smudge or smut:
A dark residue sometimes left on the surface of the sheet after pickling or annealing.

High temperature portion of an annealing cycle. In batch annealing, the soak may last for hours or days; in continuous annealing, for a minute or less.

Society of Automotive Engineers (SAE):
Organization which develops standards for automotive-related steel products.

The visual manifestation (which is flower like) of the zinc when it solidifies as the sheet emerges from the pot of molten zinc in a galvanizing line. The zinc crystal or spangle varies in size, brightness and surface relief depending on a number of factors concerning the cooling rate and pot chemistry. Lead or Antimony is added to the molten zinc in order to obtain a larger spangle or flower pattern on the surface of the steel.

Spangle free:
Suppression of the formation of spangle on the surface of galvanized steel which is accomplished through the elimination of lead or antimony in the pot chemistry and is further enhanced by use of temper rolls if needed.

The tendency of a material to slightly “springback” when cold formed rather than exactly conform to the shape of a die.

Spot pricing/spot sales:
Non-contract sales either by a mill or service center. Spot sales pricing floats with the market and can change at any time. Most steel price indexes follow spot prices.

Properties related to the ability of steel to oppose applied forces and remain in its original shape.

Steel Manufacturers Association (SMA):
A Washington, D.C.-based steel association representing the electric-arc furnace (EAF) steel industry in the public policy arena.

Steel Market Update (SMU):
High-quality newsletter and website dedicated to the North American flat-rolled steel industry.

Sticker breaks:
Arc-shaped breaks usually occurring in a line along the direction of rolling.

Ability of a material or formed part to resist deflection. All sheet steels show approximately the same stiffness; so stiffness of a part can only be changed by changing the steel thickness and the part geometry.

Strain hardening:
An increase in hardness and strength caused by plastic deformation at temperatures lower than the recrystallization range.

Stretcher strain (Luders lines):
Irregular surface patterns of ridges and valleys which develop during forming of annealed last or temper rolled aged steel.

Stress relief anneal (recovery anneal, SRA, RA):
An annealing cycle with a low temperature soak that results in high strength levels with very moderated ductility and formability.

Stretcher leveled:
Leveling where a sheet is gripped at each end and subjected to stress higher than its yield strength to remove warp and distortion (i.e. result in a flatter sheet).

Strip steel:
Flat-rolled steel produced to precise thickness/width tolerances.

Structural steel (SS):
Steel quality which has minimum strength requirements usually measured in minimum yield strength (such as 33,000 min yield – grade 33, 40,000 min yield – grade 40, etc.).

Base metal used in the next step in processing. Example: cold rolled (or full hard cold rolled) is the base metal used in a galvanizing line. Hot rolled is the base metal or substrate used to make cold rolled.

Surface imperfections:
A superficial defect that mars the surface of the steel and is detrimental to the end use. Examples include blisters and roller marks.

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 two times the sheet thickness of the metal sheet being tested.

Natural mineral containing less than 30% iron. It is the primary ore used in blast furnaces.

Tail end:
The part of a coil that makes up the inner diameter on the entry reels and the outer diameter on the delivery reels (the end of the master coil feeding into the galvanizing line which then becomes the outer wraps after coating and rewinding).

Tandem mill:
A cold-rolling mill with a series of rolls to achieve the desired thickness and surface quality of cold-rolled steel.

Temper mill (temper rolling):
A light cold rolling operation that may be used on hot-rolled, cold-rolled and some coated steels such as galvanized. Temper rolling hot rolled helps to improve flatness, minimize coil breaks and fluting by altering mechanical properties. Temper rolling cold reduced or coated sheet improves surface finish, alters mechanical properties and reduces the tendency for steel to flute during fabrication.

The segment of the continuous annealing process following the high temperature soak and quench. The steel is reheated to intermediate temperatures to soften the martensite and achieve a desirable combination of strength and ductility.

Tensile strength:
The maximum stress in uniaxial testing which a material will withstand prior to fracture. The ultimate tension strength is calculated from the maximum load applied during the test divided by the original cross-sectional area.

Tension leveling:
A mechanical operation where sheet steel is put through rolls and stretched beyond its yield point in order to improve flatness.

Theoretical minimum weight system (TMW):
Billing users for what the steel should weigh, according to its ordered thickness and width specifications rather than for what it actually weighs according to a mill weight scale. Thus, if the mills produce sheet a bit thicker or wider than ordered, as is often the case due to the inability of the mills to roll to exact dimensions, the user does not have to pay for the extra weight. Most mills have improved dimensional control considerably in recent years, as well as added an extra charge for ordering TMW.

Permissible variation in steel dimensions (thickness, width, length and diagonal).

Toll processing:
The act of third party processing (slitting, leveling, blanking, shearing, sawing, etc.) which is done for a fee.

A unit of weight measurement. A net ton or short ton is 2,000 pounds. A metric ton is 2,204.62 pounds. A gross or long ton is 2,240 pounds.

Perpendicular to the rolling direction.

Triple spot test:
A process for measuring the coating weight on coated sheet (galvanized, Galvalume, etc.) by taking three samples – one each 2 inches in from the edge and one dead center and then obtaining the average which determines the result (in simple terms it is the way to officially decide the actual coating weight on sheet steel).

The weight a truck can legally carry on the road. In the US, it is approximately 44,000 pounds. Some trucks will vary depending on whether they have an aluminum trailer vs. steel.

In prepainted steel, when the initial baking of the paint system is below that necessary for full polymerization the result will be “blocking” or sticking of the coated sheet steel.

Indicates that the material is to be used for an unexposed part for which surface finish is not of primary importance.

Vacuum degassing:
An advanced steelmaking process which removes oxygen and nitrogen under low pressure (in a vacuum) in order to produce ultra-low carbon steel for demanding formable applications. Normally performed in the ladle, the removal of dissolved gases results in cleaner, higher-quality steel.

Vitreous enameling iron:
A type of cold-rolled sheet produced for porcelain enameling and has very low carbon levels and a rough matte finish.

Virgin metal:
Steel obtained directly from ore and not used before.

Voluntary restraint agreements (VRA’s):
A compromise reached between the US and foreign steel-exporting nations. Instead of the U.S imposing punitive duties on imports, the foreign countries would “voluntarily” limit their steel exports to the US.

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.

Coils which have prohibited defects which do not allow them to be resold. Normally the material is fit for remelting only.

Out of flat condition generally introduced during the cold-rolling process. The terminology comes from the peak and valleys on the edge of the strip giving a “wave” appearance.

The point at which there is a union of steel sheet created by the application of very high temperatures.

White rust:
The corrosion product (zinc hydroxide, etc.)that forms when galvanized sheet gets wet and is unable to dry.

Work hardening:
An increase in the resistance to deformation as a result of cold-working (i.e. roll forming or similar working of the steel).

X-ray gauge:
Equipment used to measure the thickness of steel as it goes through a piece of processing equipment like a galvanizing line or slitter. On a galvanizing line the X-ray gauge is used at the beginning of the line in order to cut out off thickness substrate. It is close to the exit end of the line (after the temper mill and tension leveler) to measure the final produced thickness of the steel.

The amount of net finished product generated in relation to the initial gross amount.

Yield point:
The load or stress at which a marked increase in deformation occurs (i.e. elongation or discontinuous thickness reduction) without increasing the applied load.

Yield point elongation (YPE):
Refers to the non-uniform elongation of steel and the resulting susceptibility to strain lines (resembling cross-breaks). The deformation can be measured and while there is still no accepted industry standard, generally a YPE measurement of below 0.5% would suggest an absence of strain lines during or after stamping.

Yield ratio:
The ratio of yield strength to the tensile strength for a material.

Yield strength:
The stress point at which steel exhibits a specified deviation from a linear proportionality between load and elongation. For steel an offset of 0.2% is the reference point. If steel is sufficiently stretched, the length increases. The measurement point at which the length permanently increases by 0.2% represents the yield strength. Yield strength is lower than tensile strength, since steel will “give” before it fractures.

A chemical element with the symbol Zn. Zinc is used to coat steel to improve corrosion resistance. There is a direction correlation between the amount of zinc (or coating weight) and the rate at which the atmosphere will break down the zinc. More zinc less corrosion.