Secondary Steel Tons and Tons
Secondary Steel Coils Tons and Tons
Secondary Steel Tons and Tons

Secondary Steel Glossary

This 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.,



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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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.

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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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.

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

Crossbreaks Refer to Coil Breaks.

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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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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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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.

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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Galling Friction scratches.

Gouge A deep scratch.

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

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

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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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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.

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

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

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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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).

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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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.

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

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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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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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© 2007 Essex Trading Company/Tons and Tons