Steel Dictionary

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Steel DictionaryThis Steel Dictionary is authored by, and the copyrighted intellectual property of, Essex Trading Company. Its content information has been reviewed and approved by the metallurgical staff of ISO 17025 accredited Kieh Co., www.kieh.org.

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

A

Aging (a.k.a. Age Hardening) A process in which steel increases hardness and strength and decreases ductility over time. Special Killed (i.e., aluminum killed) prevents that condition.

AISI American Iron & Steel Institute.

Aluminized A cold-rolled sheet with aluminum applied (by hot-dip process) to the top and bottom sides. Provides excellent heat resistance and very good corrosion resistance.

Aluminum Improves ductility. Chemical symbol Al.

Aluminum Killed see Special Killed.

Annealing A process involving the controlled high-temperature heating and subsequent cooling of as-rolled (usually Full-Hard) Cold Rolled to induce softness and greater formability.

ASTM American Society for Testing and Materials. Organization which sets technical standards and specifications for steel and other materials, systems, services, etc. Generally, ASTM standards constitute the "laws" governing steel products.

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B

Bake Hardenable Steel A grade of Cold Rolled sheet with good dent resistance, especially common in automobile doors and panels.

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Band A basic form of Hot Rolled coil, without undergoing temper-leveling (skin passing). Bands are especially susceptible to wave, center buckle, crossbreaks and minor surface defects. Recently often referred to as Unprocessed Coil.

Bend, Longitudinal A bend in the direction of (with) the grain; easier bend

Bend, Transverse A bend perpendicular to (against) the grain; harder bend

Bend Radius Inside radius of a bent section, normally indicated as a factor of material thickness (T). 1-T bend diameter = ½-T bend radius.

Bend Test Tests used to determine steel ductility in which material is bent (with or against the grain).

Black Plate A specific form of light gauge (typically under .016") Cold Rolled sheet, usually used as feedstock for Tinplate.

Blank A generally-small steel sheet, typically with restrictive width, length and diagonal tolerances.

Bonderized Hot-dipped galvanized that has been phosphate-treated for improved paintability. Same corrosion resistance and formability as regular galvanized. A medium-dark grey surface with some spangle appearance.

Boron Can improve ductility and hardenability. Chemical symbol B.

Burr A thin ridge of roughness left by a cutting operation such as slitting, trimming, shearing, blanking or sawing.

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C

Camber The deviation of a coil or sheet's side edge from a straight line, the measurement taken on the concave side with a straight edge.

Carbon Main hardening element in steel. Usually, as carbon increases: tensile increases; ductility and weldability decline. Chemical symbol C.

Chemical/Chromate Treatment A chemical solution applied to galvanized to further forestall rust.

Chromium Hardens steel and prevents rust. Is prominent in Stainless steel. Chemical symbol Cr.

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Coating Weight The amount of zinc and/or aluminum applied to Galvanized, Electrogalvanized, or Aluminized sheet, normally expressed in oz./ft2.

Cold Rolling Passing of Hot Rolled coils through work rolls to reduce and tighten thickness range, improve shape and surface quality.

Columbium Often used in high-strength low-alloy steels for increased yield and tensile strengths. Also referred to as Niobium. Chemical symbol Cb.

Commercial Steel (CS) Material with mechanical properties intended for simple bending (i.e., 180° flat) or moderate forming.

Copper Reduces atmospheric corrosion resistance. Chemical symbol Cu.

Corrosion (a.k.a. Rust) Degradation of metal caused by atmospheric conditions, i.e., moisture and/or oxygen.

Corrosion, Water Stain Superficial oxidation of the surface in the absence of circulating air. Often caused by moisture trapped between closely adjacent metal surfaces such as between wraps of a coil or sheets of a stack. On Hot Rolled and Cold Rolled products the color is typically yellow, orange and/or red. On Galvanized, it's often a whitish color but can also range to black.

Crown The contour on a sheet where the thickness increases from the edges to the center.

Cut Edge More defined than mill edge, usually associated with tighter width tolerances.

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D

Dead Soft Material that has not been rolled or tempered following annealing. Characterized by very low hardness, yield strength, tensile strength with comparatively-high elongation.

Debur To remove sharp edges from a slit or cut edge.

Density The mass per unit volume of a substance. The density of carbon steel is .2833 pounds per cubic inch.

Drawing Steel For applications involving ductility beyond Commercial Steel.

Ductility The ability a sheet to allow change in shape without fracturing.

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E

Edging The process of applying a particular shape (i.e., round, square) to a slit edge.

Elasticity The ability of steel to return to its native shape and dimensions.

Electrogalvanized A thin coating of zinc applied by electrolytic deposition to a Cold Rolled substrate. Electrogalvanized usually has less corrosion resistance than hot-dipped galvanized, but with very good paintability.

Elongation A measurement of ductility/drawability. Expressed as the increase (%) of a given distance (usually 2") prior to fracture during tensile test.

Extra Smooth Galvanized Spangle-free for more uniform surface appearance and/or to improve paintability.

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F

Flatness Measurement of a sheet's conformance to a flat horizontal surface. Maximum variance from the surface (wave) is the extent to which the sheet is out-of-flat.

Forming Steel (FS) Softer than Commercial Steel, this category was previously known as Drawing Quality (DQ). It applies to coated sheet products, i.e., Galvanized, Galvannealed, Aluminized.

Fracture A break in steel, first observed at the surface.

Full Hard (FH) Steel rolled without subsequent annealing. Defined by a Rockwell higher than B84, with elevated Yield and Tensile strengths and very low elongation. Not suited for severe bending or drawing.

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G

Galvalume Cold Rolled sheet with a coating of aluminum (55%) and zinc (43%). The coating is applied in a continuous hot-dip process (similar to galvanized). It offers outstanding rust resistance (typically, 3x that of Galvanized). Galvalume can be ordered to various coating weights.

Galvanized A cold rolled or hot rolled pickled substrate upon which zinc is applied to promote corrosion resistance. There is a direct correlation between the amount of zinc applied and the steel's rust protection. Zinc can be applied by either a hot-dipped or electrolytic deposit process.

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Galvannealed A type of hot-dipped galvanized with an iron-alloy layer to enhance paintability. Has a medium-light gray, smooth appearance. Offers corrosion protection similar to regular hot-dipped Galvanized.

Gauge A number representing steel's nominal thickness (within minimum and maximum tolerances).

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H

Half Hard Referring to Cold Rolled with a Rockwell range of B70-85. Normally will only accept an approximate 90° bend on 1t diameter without fracture.

Hardness Resistance of steel to surface penetration. Usually referenced by a Rockwell hardness number, i.e., B60.

Heat The amount of steel produced from a production lot.

High Carbon steel with carbon content exceeding 0.50%.

High Strength Product intended for uses calling for higher strength levels, usually starting at 35,000# minimum yield strength.

High Strength Low Alloy Group of steels in which strength is achieved by the precise addition of alloying elements (i.e., Columbium, Vanadium, Molybdenum, Titanium).

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I

ID The inside diameter of a coil.

Impact Testing Procedure to determine the resistance of steel to fracturing under extreme conditions.

Intermediate Temper Cold Rolled hardness referenced within a 15-point Rockwell range, i.e. Quarter Hard B60-75.

Interstitial Free Steel A relatively new form of sheet product with very high ductility for deep drawing. Usually produced with very low carbon and nitrogen via vacuum-degassing.

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Iron A raw material of and the most prevalent element in carbon steel, representing about 99% of the chemical composition. Chemical symbol Fe.

I.S.M. Institute of Supply Management (formerly National Association of Purchasing Managers).

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K

Killed Steel In conjunction with Drawing Steel, material is deoxidized (using Aluminum) to allow for uniform chemical composition and freedom from age hardening.

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L

Lead Improves machinability of steel. Chemical symbol Pb.

Leveling Flattening of coil through series of rollers to reduce or eliminate distortions in thickness, shape and/or surface quality.

Light Matte Finish Cold Rolled surface intended for a smoother painted or plated coating. Usually has a profilometer range of 20-40 microinches.

Lockforming Quality (LFQ) Galvanized sheet ability to accept machine lock forming, usually a back-to-back 180° bend on 1t diameter. Commonly used in ductwork. The LFQ designation has been replaced by Commercial Steel (CS).

Lockseam Test Procedure conducted on Galvanized to determine zinc adherence to the substrate.

Low Carbon steel with carbon content below 0.25%.

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M

Manganese Contributes to hardness and strength, but less than carbon. Tends to minimize segregation. Usually beneficial to surface quality. Chemical symbol Mn.

Martensite An ultra-high strength form of steel with tensile strengths ranging from 130000-215000 psi.

Matte Finish a specified Cold Rolled surface roughness (or brightness), measured with a profilometer.

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Micrometer Instrument used to ascertain steel thickness.

Mechanical Properties Refers to structural characteristics, i.e., tensile strength, yield strength, hardness and bend ability.

Mild Steel Usually refers to carbon steel with a Carbon of 0.15% maximum.

Mill Edge Standard edge used in Hot Rolled. Does not have a definite shape; has liberal width tolerances.

Minimum Spangle In hot-dipped Galvanized, refers to a relatively small flowerlike crystallization pattern.

Molybdenum Sometimes used in high-strength low-alloy grades for increased yield and tensile strengths. Chemical symbol Mo.

Motor Lamination/Electrical Sheet A type of Cold Rolled sheet engineered for use as electromagnetic core material for electrical equipment (i.e., motors, transformers).

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N

Niobium Commonly referred to as Columbium. Often used in high-strength low-alloy steels for increased yield and tensile strengths. Chemical symbol Nb.

Nitrogen Tends to increase hardness, yield and tensile strengths. Contributes to age hardening effects. Chemical symbol N.

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O

OD The outside diameter of a coil.

Oiled Application of oil to surfaces to inhibit rust and reduce friction scratches possibly occurring during transit.

Olsen Test A method of measuring the ductility or drawing qualities of a sheet or strip.

Oxidation The exposure of steel to air (oxygen). Over time, it may result in stain, pitting and reduction in strength.

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P

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Phosphorous Reduces ductility and toughness; tends to segregate. Chemical symbol P.

Physical Qualities/Properties (aka Mechanical Qualities) Refers to values of tensile, yield, elongation, Rockwell, Erickson, Olson and/or other similar tests.

Pickling Removal of oxides and scale on Hot Rolled, through immersion in hydrochloric and/or sulfuric acids. Usually accompanied by oiling to retard subsequent oxidation.

PIW Designates pounds per inch of width of a coil. Determined by taking coil weight and dividing by width. For example, a 24000# coil at 24" wide is 1000 piw. The piw will also correlate to coil ID and OD measurements; the larger the piw, the larger the OD. Generally, larger coil PIWs are preferred since they require less production machinery setup time.

Profilometer Instrument measuring surface-roughness as an indicator of material brightness.

PSI Denotes pounds per square inch.

Pup Coil Generally a coil with less than 200 piw. (See PIW definition)

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Q

Quarter Hard In Cold Rolled, hardness of B60-75. Suitable for only limited bending and forming.

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R

Regular Matte Finish The most common Cold Rolled surface with a uniform dull finish. Usually suitable for painting. Profilometer range usually about 35-65 microinches.

Resquaring Process of blanking or shearing sheets to improve width, length and diagonal measurements.

Rimmed Steel An older type of steel manufacture in which there were significant differences in chemical composition. Rimmed product generally exhibited good surface quality. Rimmed steel is no longer produced in the North American market.

Rockwell A test measurement to determine hardness. In low carbon steels, Rockwell can indicate approximate yield strength. To get yield strength, multiply Rockwell by 1000 and subtract total by 20000. For example, a B53 Rockwell will approximate a 33000 yield (53 x 1000 - 20000).

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Rollforming Fabrication method in which steel (usually coil) is linearly, progressively deformed by passing through a consecutive series of rolls to produce a predetermined profile.

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S

SAE Society of Automotive Engineers. Helps develops standards for auto-related steel products.

Salt Spray Test A procedure to determine the coating longevity of steel when exposed to corrosive effects of saltwater.

Scotch Brite A scratch pattern surface induced by brushing with textured rolls. Can often reduce or eliminate light rust.

Sheet Flat-rolled steel generally less than .250" in thickness and wider than 12". The formula to calculate steel sheet weight is: thickness (in.) x width (in.) x length (in.) x density (.2833 lb./cubic inch).

Sidewall (SW) The contour of a coil's sides and edges. Ideally, they are free of damage, smooth and straight.

Silicon A deoxidizing element in steelmaking; very slight tendency to segregate; generally detrimental to surface quality. Chemical symbol Si.

Slab The primary steel shape from which coils are then rolled.

Slit Edge An edge produced from slitting; typically tighter width tolerances than mill edge or cut edge.

Slitting The continuous cutting if a steel coil into narrower strip widths.

Spangle In hot-dipped galvanizing, the visual manifestation of zinc when it solidifies. Appearing like a snowflake, spangle can be controlled in size and brightness. Regular Spangle is typically 3/8"- 3/4". Minimum Spangle is approximately 1/8". Extra-Smooth has no spangle as a result of surface rolling after galvanizing. Zero spangle has no spangle, as a result of zinc pot chemistry.

Special Killed Steel with improve grain structure and prolong ductility through the addition of aluminum and/or silicon and the removal of oxygen and nitrogen.

Stainless Steel Strip steels with high chrome content to impede corrosion.

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Stamping Metalworking operation involving the cutting and forming of steel using tooling and dies.

Strain The amount of elongation or compression when steel is subjected to a specific load.

Stress The force per unit area caused by externally produced forces.

Stretcher Leveled Flatness exceeding commercial tolerances, often specified for panels or similar applications.

Strip Steel flat-rolled steel produced to precise thickness and/or narrow width tolerances.

Structural Steel (SS) A steel quality specified when the minimum finished part strength (usually in load-bearing applications) is required. Commonly specified in minimum yield strength (i.e., 33000 psi, 40000 psi, 50000 psi, or 80000 psi).

Sulfur A chemical element that tends to lower ductility and weldability; prone to foster segregation; impairs surface quality. Chemical symbol S.

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T

T-Bend A mechanical procedure in which a steel sheet is bent 180° with the inside bend diameter expressed in terms of the material thickness. A bend of 1-T is equivalent to the material thickness; a 2-T bend equals twice the material thickness.

Tandem Mill A progressive series of rolling mill stations in which coils are cold-worked, primarily to reduce thickness and improve flatness.

Temper Refers to steel hardness resulting from mechanical, chemical and/or thermal properties. Generally produced by cold-reduction, typical classifications are soft, quarter-hard, half-hard, three-quarter hard, and full hard.

Temper-Passed/Rolled A cold reduction of a sheet, passing through a series of rolls, to improve flatness and surface finish. Usually reduces or eliminates crossbreaks, center buckle.

Tensile Strength The maximum strength that steel can withstand prior to fracture. Tensile testing measures maximum load ratio in relation to original cross-section area.

Tension Leveled Flatrolled product that has been passed through rollers which stretch the material beyond its yield point, producing improved flatness.

Tin Chemical symbol Sn.

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Tin-Plate Very light gauge Cold Rolled with electrolytically-deposited tin on both sides. Used for the manufacture of cans.

Titanium Often used in high-strength low-alloy steels for increased yield and tensile strengths. Also used in EDDS steels to increase ductility. Chemical symbol Ti.

Tolerance permissible variation in dimensions (thickness, width, length, diagonal).

Ton A unit of weight measurement. A net ton is 2,000 pounds. A metric ton is 2,204.6 pounds. A gross (or long) ton is 2,240 pounds.

Transverse Perpendicular to the direction of rolling.

Traverse Winding a.k.a. oscillate, coils that are wound like a fishing reel (in contrast to ribbon winding).

Triple Spot Test A process for measuring the coating weights, representing the average weight from three samples taken across a coil/sheet width.

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U

Ultimate Strength See tensile strength.

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V

Vacuum Degassing An advanced steelmaking process that removes oxygen and nitrogen. It is used to produce very pure ultra-low carbon steels with high drawing and formability features, especially for automotive body applications.

Vanadium Often used in high-strength low-alloy steels for increased yield and tensile strengths. Chemical symbol V.

Vitreous Enameling Iron A type of Cold Rolled sheet produced for porcelain enameling. Has very low carbon levels and a rough matte finish (typically 55+ microinches).

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W

Weld A joining or union of steel, created by the application of very high temperatures.

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Weldability The adaptability of steel to welding, typically influenced by chemical composition, surface finish, coating type and weight.

Work Hardening The increase in resistance to deformation as a result of cold-working, i.e., rolling, rollforming.

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Y

Yield The amount of net finished product generated in relation to the initial gross amount. (Not to be confused with Yield Point.)

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

Yield Point Elongation (YPE) Refers to a non-uniform elongation of steel and resulting susceptibility to Lüders bands (surface strain lines, resembling crossbreaks). The deformation can be measured and while there is no accepted industry standard, generally a YPE measurement below 0.5% would suggest an absence of strain lines during/after stamping.

Yield Strength The stress at which steel exhibits a specified deviation from a linear proportionality between load and elongation. For steel (and many other metals) an offset of 0.2% is the reference point. If steel is sufficiently stretched, the length is increased. The measurement point at which the length permanently increases by 0.2% represents the yield strength. For example, if a load is applied upon a steel sample, any 1.000" of its length becomes 1.002" after loading to the yield strength. Yield strength is lower than tensile strength, since the steel will "give" before it fractures.

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Z

Zinc A chemical element applied (either hot-dipped or electrolytically) to steel to improve corrosion resistance. There is a direct correlation between the zinc coating weight and rate of atmospheric corrosion; the more the zinc, the slower the corrosion. Chemical symbol Zn.

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Secondary Steel GlossaryThis Secondary Steel Glossary is authored by, and the copyrighted intellectual property of, Essex Trading Company. Its content information has been reviewed and approved by the metallurgical staff of ISO 17025 accredited Kieh Co., www.kieh.org.

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

A

Age Hardening A process in which steel increases hardness and strength and ordinarily decreases ductility over time. Special Killed (i.e., aluminum killed) prevents that condition.

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B

Blister In coated products, a defect caused by the formation of air bubbles in a zinc or aluminum coating. In uncoated, refers to a raised spot on the steel surface evidencing inclusions and small laminations.

Bow, Longitudinal Curvature in the plane of sheet or plate in the rolling direction. Usually caused by unbalanced stresses between the top and bottom surfaces of the rolled product.

Bow, Transverse Curvature across the rolling direction of sheet. A more severe case can result in a center buckle. Usually caused by an unbalanced curvature of the top and bottom mill rolls during processing.

Buckle A distortion (usually repetitive) in flatness during rolling.

Buckle, Arbor Bends, creases, wrinkles, or departures from flat, occurring perpendicular to the slit edge of a coil and which are repetitive in nature, with severity decreasing as the distance increases in the coil from the original source. Often they are found at/near the coil ID or OD.

Buckle, Center Undulations (wavy regions) in the center of the metal.

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Buckle, Edge Undulations (wavy regions) along the edge(s) of the metal.

Build Up Coil A coil made by welding (or stitching) together two or more coils to make a larger one, often for efficiency during the galvanizing process.

Burr A thin ridge of roughness left by a cutting operation such as slitting, trimming, shearing, blanking or sawing.

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C

Camber The deviation of a coil or sheet's side edge from a straight line, the measurement taken on the concave side with a straight edge.

Center Buckle A wave condition in the coil/sheet, caused by the center (in the rolling direction) being longer than the edges.

Coating Build-Up A coating thickness greater than nominal due to uneven application.

Coating Drip A non-uniform extraneous deposit of coating on the coated sheet.

Coating, High or Low Failure to meet the proper coating weight range.

Coating Ridge On coated steels, a hump in the rolling direction usually caused by improper wiping when exiting the coating tank.

Coil Breaks Parallel creases or ridges across the width of a sheet (transverse to rolling direction).

Coil Set Longitudinal bow in an unwound coil, caused by the action of winding the sheet into a coil.

Collapsed Coil Out-of-round condition of coil often due inappropriate tension during rewinding operations. The internal diameter (ID) is compressed.

Corrosion (a.k.a. Rust) Degradation of metal caused by atmospheric conditions, i.e., moisture, oxygen, chemicals. There are varying degrees of severity, i.e., extent across surface, depth of penetration into surface.

Cracks, Edge Tears or discontinuity on the coil/sheet edge.

Crease A sharp deviation from flat in the sheet which is transferred from processing equipment subsequent to the roll bite. If longitudinal, typical sources include idler rolls, leveler rolls, segmented rolls and slitter spacers. If transverse, typical sources include mandrels, coil ends and racks.

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Crossbow A curvature across the width of the strip perpendicular to the rolling or coiling direction.

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D

Dent A sharply defined surface impression on the metal which may be caused by a blow from another object.

Dirt Foreign debris imbedded in or under the coating from rolling or post-rolling operations.

Dross Drops of sediment atop galvanized sheet.

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E

Edge, Belled Excessive buildup of material on edge(s) during a rewinding operation. Typical causes include excessive edge burr, turned edge, and "dog bone" shaped cross sectional profiles.

Edge Break Edge(s) with a crossbreak surface defect.

Edge Buckle Similar to center buckle but occurring along one or both edges.

Edge Buildup A heavier coating (zinc, aluminum) concentration at the edge(s) rather than the center of the coil.

Edge, Corrugated Severe bending (like a washboard) along a coil/sheet edge caused by improper rolling practice. Usually will occur in a belled edge shape.

Edge, Damaged Sheet/coil edge that has been bent, torn or scraped by an object.

Edge Wave A condition in the band of steel where the edges (in the direction of rolling) are longer than the center.

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F

Flaking A condition in coated sheet where portions of the coating become loosened due to inadequate adhesion.

Fluting A breaking or kinking condition caused by aging or improper processing.

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Friction Scratches A series of short abrasions caused by the rubbing of laps or sheets. Also called galling. Scratches are shallow; gouges are deep.

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G

Galling Friction scratches.

Gouge A deep scratch.

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H

Heat Ridge Usually referring to Hot Rolled, a hump in the rolling direction usually resulting from a trapped center buckle after cold reduction.

Heavy Coating Excessive amount of coating (i.e., zinc or aluminum) applied to the surface.

Hole A metal void, usually caused by a non-metallic inclusion during rolling.

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I

Inclusions Particles of foreign material (i.e., oxides, silicates, sulfides) in steel, usually compromising physical integrity.

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K

Kink An abrupt bend or deviation from flat which is caused by localized bending during handling.

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L

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Lamination (a.k.a. Segregation or Piping) Defect caused by the presence of internal blisters, seams or inclusions. Harmful to structural integrity; could cause steel fracturing.

Lap Weld Coil ends are "lapped" over one another and welded or stitched for production purposes. As a result, the thickness of the steel is doubled at the weld area.

Line Stop Referring to coated steels, an area of a coil where the coating line was halted. This region is usually characterized by irregular and questionable coating integrity.

Loose Wrap A coil that is not wound tight due to insufficient tension when winding.

Lüders Lines Elongated surface markings or depressions appearing in patterns caused by localized plastic deformation that results from a discontinuous yield and resulting yield point elongation.

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M

Mark, Arbor Surface damage at/near coil ID caused by roughened, damaged or non-circular arbor.

Mark, Bite Lines which are generally perpendicular to the rolling direction, caused by the leading end of the metal entering the leveling rolls resulting in minor surface disruptions. These disruptions then transfer to the surface of the rolled metal in subsequent rotations.

Mark, Chatter (Roll or Leveler) Close, intermittent lines transverse to the rolling direction.

Mark, Inclusion Appearance of surface where actual inclusion or the void it left is observed.

Mark, Knife A continuous scratch (which may also be creased) near a slit edge, caused by sheet contacting the slitter knife.

Mark, Roll A small repeating raised or depressed area on rolled products caused by the opposite condition on a roll. The repeat distance is a function of the offending roll diameter.

Mark, Roll Bruise A greatly enlarged roll mark whose height or depth is very shallow.

Mark, Rub A large number of very fine scratches or abrasions. A rub mark can occur by metal-to-metal contact, movement in handling and movement in transit.

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Mark, Roll Skid Scratch-like, repeating patterns perpendicular to rolling direction. Usually caused by work roll misalignment.

Mark, Whip Surface abrasions generally diagonal to rolling direction. Typically caused by fluttering of coil between leveling rolls.

Mixed Coil A fully-coated coil whose surfaces contain more than one coating, i.e., both regular galvanized (bright) and galvannealed (dull).

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N

Necking A narrowing of coil width caused by improper tension in rolls during production.

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O

Off Gauge Thickness deviation from the ordered specification and/or tolerances.

Oil Can A tight wave or undulation, also referred to as a trapped center buckle.

Orange Peel Surface roughening on formed products which occurs when large grains in the metal are present.

Oscillation Uneven wrap in coiling and lateral travel during winding. Improper alignment of rolls over which the metal passes before rewinding and insufficient rewind tension are typical causes.

Overpickled Excessively-prolonged exposure to pickling acids, usually resulting in a burnt or stained surface.

Overwidth Width exceeding the ordered dimension.

Oxidation Rust, corrosion.

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P

Peeling On galvanized, aluminized and other metallic-coated steels, the separation of the coating from the steel substrate.

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Pick-Off The transfer of portions of the coating from one surface of the sheet to an adjacent surface due to poor coating adhesion.

Pickle Stain or Burn Surface discoloration due to excessive acid solution and/or steel's exposure to same.

Pickle Patch An area of heavy scale that has not been removed after pickling or other processing.

Pickup, Roll Small particles of debris trapped in the rolls and transferred to the sheet surface. Could apply to Cold Rolled or coated sheet.

Pinchers Fern-like creases usually diagonal to the rolling direction.

Pinholes A coating defect consisting of random small round holes. The open area (pinhole) exposes the steel substrate. Usually caused by laminations, inclusions, scratches or improper lubricant.

Piping Similar to lamination, a void in the steel's thickness.

Pitting (Rust) A severe form of oxidation causing sharp depressions in the steel surface.

Pitting (Coated) Random small depressions in the coating. Similar to pinholes, except that pitting does not reveal the bare substrate.

Powdering A problem in which Galvannealed's iron-zinc coating dislodges from the steel substrate.

Pup Coil A coil with relatively small P.I.W., typically under 200. They often contain defects, i.e., dents, dings, scratches.

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R

Roping A rope-like appearance in the rolling direction after the metal has undergone severe deformation. This condition is caused by the presence of irregular grains in the rolled product before being deformed.

Ragged Edges Sheet edges that are cracked, torn, ragged, split and/or otherwise damaged.

Reel Breaks Surface blemishes (indicated by kinks across the coil width) caused by the winding arbor.

Reel Kinks Horizontal creases near a coil ID (or OD if rewound).

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Ridge A surface hump down the length of a sheet/coil.

Roll Grind The uniform ground finish on the work rolls which is imparted to the sheet or plate during rolling.

Rolled-in Metal An extraneous chip or particle of metal rolled into the surface of the product.

Rolled-in Scale A defect resulting from scale being rolled into the steel surface.

Roping A rope-like effect in the rolling direction after steel has been subjected to deep forming/drawing.

Rust Corrosion caused by exposure over time to atmosphere, chemicals or other injurious elements. Usually, Hot Rolled and Cold Rolled turn orange/red. Galvanized and Aluminized turn white to black.

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S

Scale Iron oxides which form on the surface of Hot Rolled during or subsequent to rolling. Scale can be removed by Pickling.

Scratch Scoring or indentation of varying degree in the surface. Usually caused by rollers or during handling.

Seam A surface crack sometimes caused during casting or hot-rolling.

Secondary Steel Material that does not meet the original customer's specifications in terms of thickness, width, surface, chemistry or physical properties. Sold at a discount compared to prime steel, secondary may be quite suitable for other applications.

Segregation A nonuniformity in chemical composition occurring during solidification. Often associated with internal defects, i.e., lamination and piping.

Skin Lamination Seam or inclusion at surface resembling a blister. Could lead to metal fracture.

Skip An area of uncoated sheet which is frequently caused by equipment malfunction.

Sliver Thin fragments of steel which are part of the material but only partially attached. Typically caused by surface damage or internal inclusions which are subsequently rolled.

Smudge A dark film of debris, sometimes covering large areas, deposited on the sheet during rolling.

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Snaking A series of reversing lateral bows in coil products. This condition is caused by a weaving action during an unwinding or rewinding operation.

Spelter Referring to Galvanized or Aluminized, a severe coating buildup resulting in a non-uniform surface.

Spooled Coil A coil having edges that are turned up or down (like a spool of thread).

Stain, Oil Surface discoloration which may vary from dark brown to white and is produced during thermal treatment by incomplete evaporation and/or oxidation of the surface by the lubricants.

Starvation Non-uniform coating application which results in absence of coating in certain areas. This condition can be caused by mismatch of applicator roll and sheet surface velocities.

Streak, Coating A banded condition caused by non-uniform coating during the initial application process.

Streak, Dirt Surface discoloration which may vary from grey to black, is parallel to the direction of rolling, and contains rolled in foreign debris. It is usually extraneous material from an overhead location that drops onto the rolling surface and is shallow enough to be removed by etching or buffing.

Streak, Grinding A streak with a helical pattern appearance transferred to rolled products from the work rolls.

Streak, Leveler A streak on the sheet surface in the rolling direction caused by transfer from the leveler rolls.

Streak, Roll A non-uniform surface appearance parallel to the rolling direction. It is caused by an uneven wiping action on the upper backup roll(s) of a mill which transfers first to the work roll and then to the rolled product.

Stretcher Strains Irregular lines that develop during drawing or stretching. Also called fluting.

Striation A coating flow defect appearing as near-parallel lines.

Surface Tear Minute surface cracks on rolled products which can be caused by caster cracks.

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T

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Telescoping Lateral stacking, primarily in one direction, of wraps in a coil so that the sidewall of the coil is conical rather than flat. Usually caused by improper alignment of rolls over which the steel passes before rewinding.

Transit Rust Oxidation occurring during shipment. Typically appears most prominently on ID and OD wraps, top and bottom sheets, and at edges. It may manifest in sporadic spots within coil or sheet bundle.

Transition Coil A coil that is partially Electrogalvanized coated and partially bare Cold Rolled.

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V

Void An internal cavity produced during the solidification process during casting.

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W

Water Stain Superficial oxidation of the surface with a water film, in the absence of circulating air, held between closely adjacent metal surfaces such as between wraps of a coil or sheets of a stack. The appearance varies from iridescent in mild cases to white, gray, or black in more severe instances.

Wave An out-of-flat condition relative to the order or ASTM flatness specifications. Can occur across the width or merely at edge(s).

Weld (Coil) Area where coils have been welded together to form a single, longer length for more efficient production. The area near the weld is typically of poor quality in terms of strength, surface and coating adhesion.

White Rust On galvanized, corrosion that occurs when material is exposed to moisture and is unable to quickly dry, often between adjacent wraps or sheets. Varies in severity and coverage area.

Wrap-Loose A condition in a coil due to insufficient tension which creates a small void between adjacent wraps.

Wrinkling A coating defect of small ridges or folds resembling a small prune skin.

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Y

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Yield Point Elongation (YPE) Refers to a non-uniform elongation of steel and resulting susceptibility to Lüders bands (surface strain lines, resembling crossbreaks). The deformation can be measured and while there is no accepted industry standard, generally a YPE measurement below 0.5% would suggest an absence of strain lines during/after stamping

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