ALUMINUM COIL SINCE 1915

Glossary

Abrasion Aerospace Alloys Aging Alclad Alligatoring Alloy Alloy Selection Alloying Element Aluminum - chemical symbol Al Aluminum Association AMS Annealing Anodizing Anodizing Quality ANSI AQ ASME ASTM AWS Bauxite Belled Edge Bend Radius Bend Test Blank Blister Bow, Lateral Bow, Longitudinal Bow, Transverse Brazing / Brazing Sheet Bright Dip Brittleness Bruise Buckle Buckle, Center Buckle, Edge Buckle, Quarter Buffing Buff Streak Burr Butt Welding Camber Canning Chatter Marks Chemical Brightening Chemical Composition Clad Products Clockwise Coil Coil Orientation Coil Set Coil Set, Reversed Coiled Sheet Coils Cold Rolling Cold Working Commercial Tolerance Common Alloys Coned-out Coil Continuous Casting Controlled Atmosphere Brazing (CAB) Conversion Coatings Corrosion Corrosion, Water Stain Counter-Clockwise Coil Cross Direction Cross-Hatched Surface Crown Cup Fracture Cut Cutter Mark DC (Direct Chill) Casting Deburring Deep Drawing Dent Dent, Expansion Dent, Repeating Die-Lines Dish Drawing Drawn-In Scratch Drawn Product Ductility Earing Ears Edge, Belled Edge Ripple Edge Strain or Edge Breaks Elastic Limit Elastic Strain Electrical Conductivity Electrobrightening Elongation Embossing Etching Extensometer Eye to the Side Eye to the Sky F Temper Fatigue Limit Fiber Fin Stock Flatness Flat Sheet Flow Lines Flow Stress Flux Dip Brazing FMEA Foil Formability Four-High Mill Fretting (Fretting Corrosion) Friction Gouges or Scratches Full Hard Temper Galling Gauge Gouge Grain Grain Coarsening Grain Size HXX Temper H1X Temper H2X Temper H3X Temper Handling Mark Hair, Slitter Heat Treating / Heat Treated Heat-Treatable Alloys Herringbone Hole Holiday Hot Mill Pickup ID Inclusion Inclusion, Stringer Ingot Interleaving Ironing ISO Isotropy JIS Knife Mark Lamination Lateral Bow Leveling / Leveled Longitudinal Bow Looper Loose Wrap Luder Lines Machinability Malleability Mark Mark, Chatter Mark, Handling Mark, Inclusion Mark, Knife Mark, Roll Mark, Rub Mark, Traffic Mechanical Properties Mill Edge Mill Finish Minimum Recommended Bend Radii Modulus of Elasticity Modulus of Elasticity (tension) Mult Necking Nick Non-Ferrous Metals Non Heat-Treatable Alloy OD O Temper Oil Stain Orange Peel (effect) Oscillation Oxidation Pad Pancake coil Parabolics Physical Properties Pickup Pit (defect) Pounds Per inch of Width (PIW) Polished Surface PPAP Published Tolerances PVC QS 9000 Quarter Hard Quarter Buckle Quenching Ra Reflector Sheet Reroll Stock Rockwell Hardness (Test) Roll Forming Roll Chatter Roll Mark Roll Pickup Rolled-In Scratch Rolling Rolling Direction Roping Rz SAE Scratch Scratch, Friction Scratch, Handling Scratch, Oscillation Scratch, Rolled-In Scratch, Tension Sendzimir Mill (Z Mill) Shear Strength Sheet Slit Edges Slitting Slitter Hair Sliver (defect) Smut Solution Heat Treatment Stain, Oil Stain, Water Stamping Strain Stress Stress-Rupture Test Stretch Forming Stretcher Leveling Strip Structure Substrate Surface Roughness Tandem Mill Telescoping Temper Tensile Strength Thickness Tolerance Traffic Marks Transverse Bow Transverse Direction Ultimate Strength Ultimate Tensile Strength (UTS) Vacuum Brazing Water Stain Wavy Wavy Edge Weldability Workability Wrought Product Yield Point Yield Strength Z-Mill Abrasion Rubbing, grinding, or wearing away by friction. back to top Aerospace Alloys Heat treatable alloys in the 2000 and 7000 series, including 2024 and 7075, are often used in aerospace applications and are sometimes referred to as aerospace alloys. Tighter gauge tolerances are given for this group of alloys in ANSI H35.2. back to top Aging (called Ageing in UK) Precipitation from solid solution resulting in a change in properties of an alloy, usually occurring at room temperature (natural aging), or at elevated temperature (artificial aging). back to top Alclad Composite sheet produced by bonding either corrosion-resistant aluminum alloy or aluminum of high purity to base metal of structurally stronger aluminum alloy. The coatings are anodic to the core so they protect exposed areas of the core electrolytically during exposure to corrosive environment. back to top Alligatoring Also called lamination, an internal crack or separation parallel to the rolled surfaces. Typically a result of insufficient trim at hot rolling. back to top Alloy A substance having metallic properties and composed of at least two or more elements of which at least one is an elemental metal. Aluminum alloys for sheet products are identified by a four digit numerical system which is administered by the Aluminum Association. See "Aluminum Alloy Designations" section of the Technical Manual. back to top Alloy Selection See the "Selection Guide for Aluminum Alloys and Tempers" Table in the Technical Manual section. back to top Alloying Element An element added to a metal, and remaining in solid solution in the metal, that effects changes in structure and properties. back to top Aluminum - chemical symbol Al (called Aluminium in UK) Element No. 13 of the periodic system; Atomic weight 26.97; silvery white metal of valence 3; melting point 1220 (degrees) F; boiling point approximately 4118 (degrees) F.; ductile and malleable; stable against normal atmospheric corrosion. Aluminum is used extensively in articles requiring lightness, corrosion resistance, electrical conductivity, etc. See "Benefits of Aluminum" section in the Technical Manual. back to top Aluminum Association The Aluminum Association, based in Washington, D.C., represents U.S. and foreign-based primary producers of aluminum, aluminum recyclers and producers of aluminum fabricated products. United Aluminum is a founder member of the Association. back to top AMS Abbreviation for Aerospace Material Specification. back to top Annealing Thermal treatment used to soften metal by removing stress created from cold working. back to top Anodizing (called Anodising in UK) The process of coating aluminum by anodic treatment resulting in a thin film of aluminum oxide of extreme hardness. A wide variety of dye colored coatings are possible by impregnation in process. back to top Anodizing Quality An indication that special attention has been paid to the metallurgical characteristics and surface quality of the aluminum sheet to assure that a uniform and blemish-free decorative anodic film will form during anodizing. United Aluminum can meet your anodizing quality needs. back to top ANSI Abbreviation of American National Standards Institute. Dimensional tolerances for aluminum sheet and coil are covered by ANSI H35.2. back to top ASME Abbreviation for American Society of Mechanical Engineers. back to top ASTM Abbreviation for American Society For Testing Material. An organization for issuing standard specifications on materials, including metals and alloys. Most aluminum sheet produced by United Aluminum is covered by ASTM B209. back to top AWS Abbreviation for American Welding Society. back to top Bauxite Commercially mined ore of aluminum back to top Belled Edge Excessive buildup of material on edge(s) of a coil during a rewinding operation. Typical causes include excessive edge burr, turned edge, and "dog bone" shaped cross sectional profiles. back to top Bend Radius The inside radius of a bent section. See "Minimum Recommended Bend Radii" in Technical Manual. back to top Bend Test Various tests which are used to ascertain the toughness and ductility of a metal product, in which the material is bent around its axis and/ or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. back to top Blank A piece of metal cut or formed to regular or irregular shape for subsequent processing by forming, bending or drawing. Typical Blanks include circles and square shapes. back to top Blister A defect in metal, on or near the surface, resulting from the expansion of gas in a subsurface zone. back to top Bow, Lateral See "Camber". back to top Bow, Longitudinal Curvature in the plane of sheet or coil in the rolling direction. back to top Bow, Transverse Curvature across the rolling direction of sheet or coil. back to top Brazing / Brazing Sheet Some aluminum sheet products are made up of a strong core alloy that is clad with a thin layer of a high-silicon alloy which has a much lower melting point than the core (see also "Clad Products"). This allows a complex shape, such as a car radiator, to be fabricated then heated to a temperature that is sufficient to melt the cladding while leaving the core intact. The thin skin of oxide film that covers the surface of aluminum needs to be removed for effective brazing. There are three common brazing methods:      Flux-Dip Brazing      The component is immersed in a molten salt which acts as a flux as well as a heat source for melting the clad layer. The fluxes      are corrosive and all traces must be removed after brazing.      Controlled Atmosphere Brazing (CAB)      Sometimes also described by the trade name "Nocolok", this process uses a non-corrosive powdered flux and an inert      gas atmosphere.      Vacuum Brazing      Components are heated in a high vacuum, completely free of oxygen. The clad alloy must contain magnesium as an alloying      addition. At the brazing temperature, the heat and vacuum causes the magnesium to "boil" out of the molten metal thereby breaking      up the brittle oxide skin into small, harmless shards. See United Aluminum Capabilities data for information on Brazing Sheet offered back to top Bright Dip (also called Chemical Brightening) An acid/copper solution into which pieces made from high-purity aluminum are dipped in order to obtain a clean, bright surface. The reaction is entirely chemical with no external source of electrical current. See also Electrobrightening. back to top Brittleness The tendency of a metal or material to fracture without undergoing appreciable plastic deformation. back to top Bruise A greatly enlarged roll mark whose height or depth is very shallow. back to top Buckle A surface distortion of bulges and/ or hollows occurring along the length metal with otherwise flat edges. back to top Buckle, Center Undulation (wavy region) in the center of the metal. back to top Buckle, Edge Undulation (wavy region) along the edge(s) of the metal. back to top Buckle, Quarter Undulation (wavy region) which occurs approximately at both quarter points across the width. back to top Buffing A mechanical finishing operation in which fine abrasives are applied to a metal surface by rotating fabric wheels for the purpose of developing a lustrous finish. back to top Buff Streak A dull continuous streak caused by smudge buildup on a buff used at shearing or other operations. back to top Burr A thin ridge of roughness along the edge of slit or sheared coil or sheet. back to top Butt Welding Joining two edges or ends by placing one against the other and welding them. back to top Camber See also "Lateral Bow": An edgewise curvature referring to the deviation of side edge from a straight line. See "Lateral Bow Limits" section of Technical Manual. back to top Canning A dished distortion in a flat or nearly flat surface, sometimes referred to as oil canning. back to top Chatter Marks Intermittent parallel indentations or marks appearing at right angles to edge of strip forming a pattern caused by roll vibrations. back to top Chemical Brightening See Bright Dip and Electrobrightening back to top Chemical Composition Composition in percent by weight according to the Aluminum Association. See "Chemical Composition Limits for Aluminum Alloys" Table in the Technical Manual back to top Clad Products Metallurgicaly bonded composite sheet of differing core and surface alloys, 1 or 2 sides. back to top Clockwise Coil With the coil core vertical ("eye to the sky") and viewed from above, a trace of the metal edge from the ID to the OD involves clockwise movement. back to top Coil Orientation Clockwise Coil: With the coil core vertical ("eye to the sky") and viewed from above, a trace of the metal edge from the ID to the OD involves clockwise movement. Counter-Clockwise (Anti-Clockwise) Coil: With the coil core vertical ("eye to the sky") and viewed from above, a trace of the metal edge from the ID to the OD involves a counter-clockwise (anti-clockwise) movement. back to top Coil Set Also called Coil Curvature. A lengthwise curve or set found in coiled strip metals following its coil pattern. A departure from longitudinal flatness. Can be removed by roller or stretcher leveling from metals in the softer temper ranges. back to top Coil Set, Reversed Longitudinal bow in an unwound coil in the direction opposite to the curvature of the wound coil. back to top Coiled Sheet Sheet in coils with slit edges. back to top Coils Coiled flat sheet or strip metal- usually one continuous piece or length. back to top Cold Rolling Rolling metal at a temperature below the softening point of the metal to create strain hardening (work-hardening). Same as cold reduction, except that the working method is limited to rolling. Cold rolling changes the mechanical properties of strip and produces certain useful combinations of hardness, strength, stiffness, ductility and other characteristics known as tempers. back to top Cold Working Plastic deformation, such as rolling, hammering, drawing, etc., at a temperature sufficiently low to create strain-hardening (work-hardening). Commonly, the term refers to such deformation at normal temperatures. back to top Commercial Tolerance A term sometimes used synonymously with "Standard Tolerance". Typically refers to those tolerance limits published by the Aluminum Association. See "Aluminum Sheet & Coil Published Dimensional Tolerances" section of the Technical Manual back to top Common Alloys One of several terms used in the industry to identify the non-heat-treatable classes of alloys-alloys identified in the four-digit numbering system by having as their first digit a "1", a "3", a "5". Strengthened by cold working rather than thermal processes. back to top Coned-out Coil Telescoping: Lateral stacking, primarily in one direction, of wraps in a coil so that the edges of the coil are conical rather than flat. See also "Oscillation." back to top Continuous Casting A casting technique in which an ingot, billet, tube, or other shape is continuously solidified while it is being poured, so that its length is not determined by mold dimensions. back to top Controlled Atmosphere Brazing (CAB) Sometimes also described by the trade name "Nocolok", this process uses a non-corrosive powdered flux and an inert gas atmosphere. See United Aluminum Capabilities data for information on Brazing Sheet offered. back to top Conversion Coatings Proprietary solutions, usually of a chromate or a phosphate variety, which when applied to a clean aluminum surface will serve to increase the metal's resistance to corrosion and provide a good base for paint adhesion. back to top Corrosion Deterioration of a metal by chemical or electrochemical reaction with its environment. Aluminum corrosion characteristics include general white staining (white rust) as well as pitting. back to top Corrosion, Water Stain Superficial oxidation of the surface with a water film, in the absence of circulating air, held between closely adjacent metal surfaces. See "Water Stain and its Prevention" Section of the Technical Manual back to top Counter-Clockwise (Anti-Clockwise) Coil With the coil core vertical ("eye to the sky") and viewed from above, a trace of the metal edge from the ID to the OD involves a counter-clockwise (anti-clockwise) movement. back to top Crazing A macroscopic effect of numerous surface tears, transverse to the rolling direction, which can occur when the entry angle into the cold mill work rolls is large. back to top Cross Direction (in rolled or drawn metal) The direction at right angles to the direction of rolling or drawing. back to top Cross-Hatched Surface A surface having innumerable minute cracks running normal to the direction of working. back to top Crown A contour on a sheet or roll where the thickness or diameter increases from edge to center. back to top Cup Fracture (Cup-and-Cone Fracture) Fracture, frequently seen in tensile test pieces of a ductile material, in which the surface of failure on one portion shows a central flat area of failure in tension, with an exterior extended rim of failure in shear. back to top Cut (also called Pad or Pancake Coil) Common term for a narrow-slit coil. See also Mult. back to top Cutter Mark See Knife Mark back to top DC (Direct Chill) Casting A continuous method of making ingots or billets for sheet or extrusion by pouring the metal into a short mold. The base of the mold is a platform that is gradually lowered while the metal solidifies, the frozen shell of metal acting as a retainer for the liquid metal below the wall of the mold. The ingot is usually cooled by the impingement of water directly on the mold or on the walls of the solid metal as it is lowered. The length of the ingot is limited by the depth to which the platform can be lowered; therefore, it is often called semi continuous casting. back to top Deburring A method whereby the raw slit edge of metal is removed by rolling or filing. back to top Deep Drawing Forming a deeply recessed part by forcing sheet metal to undergo plastic flow between dies. May require "deep draw" quality metal. See Capabilities back to top Dent A sharply defined surface impression on the metal which may be caused by a blow from another object. back to top Dent, Expansion Surface deviation from flat generated by expansion of vapor during thermal treatment of cold rolled coiled sheet. back to top Dent, Repeating Repeating depression caused by a particle adhering to a rotating roll over which the metal has passed. back to top Die-Lines Lines of markings caused on drawn or extruded products by minor imperfections in the surface of the die. back to top Dish A concave surface departing from a straight line edge to edge. Indicates transverse or across the width. back to top Drawing Forming recessed parts by forcing the plastic flow of metal in dies. See also Deep Drawing. back to top Drawn-In Scratch A scratch occurring in the fabricating process and subsequently drawn over making it relatively smooth to the touch. back to top Drawn Product A product formed by pulling material through a die. back to top Ductility The ability of a material to deform plastically without fracturing, being measured by elongation or reduction of area in a tensile test, by height of cupping in an Erichsen test or by other means. back to top Earing Wavy projections formed at the open end of a cup or shell in the course of deep drawing because of difference in directional properties. Also termed scallop. Also: Isotropy back to top Ears Wavy symmetrical projections formed in the course of deep drawing or spinning as a result of directional properties or anisotropy in sheet. Ears occur in groups of 4 or 8 with the peaks of the projections located at 45 degrees and/or at 0 to 90 degrees to the rolling direction. Degree of earing is the difference between average height at the peaks and average height at the valleys, dividing by average height at the valleys, multiplied by 100 and expressed in percent. back to top 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. back to top Edge Ripple Undulation (wavy region) along the edge(s) of the metal. Also referred as Edge Buckle. back to top Edge Strain or Edge Breaks Creases extending in from the edge of the temper rolled sheet. back to top Elastic Limit Maximum stress that a material will stand before permanent deformation occurs. The maximum stress to which a material may be subjected without any permanent strain remaining upon complete release of stress. back to top Elastic Strain Dimensional changes accompanying stress where the original dimensions are restored upon release of the stress. back to top Electrical Conductivity The capacity of a material to conduct electric current. For aluminum, this capacity is expressed as a percentage of the International Annealed Copper Standard which as a resistivity of 1/58 ohm-mm2/metre at 20° C and an arbitrarily designed conductivity of unity. See "Typical Physical Properties" Table in Technical Manual back to top Electrobrightening (also called Electro Polishing and Electrolytic Brightening) Improving the specular reflectivity of a metal surface by electrochemical dissolution. High-purity aluminum is required for good brightness. See also Bright Dip) back to top Elongation The increase in the gauge length of a tensile test specimen, between two marks 2 inches apart, expressed as a percent, after stressing the specimen in tension to the point of fracture. back to top Embossing Raising or indenting a design in relief on a sheet or strip of metal by passing between two patterned rolls. back to top Etching Subjecting the surface of a metal to preferential chemical or electrolytic attack to reveal structural details. back to top Extensometer A test apparatus for indicating the deformation of metal while it is subjected to stress. back to top Eye to the Side Packed on a skid so that the coils are standing on edge and the ID is horizontal (less common) back to top Eye to the Sky Packed on a skid so the coils are laying flat and ID is vertical (common packing procedure) back to top F Temper "As Fabricated" Applies to products of rolling or forming where there is no special control over the thermal or work hardening conditions. Mechanical properties may vary widely. This temper usually applies to sheet products at intermediate stages of production. See "Aluminum Temper Designations" section of Technical Manual back to top Fatigue Limit The maximum stress below which a material can presumably endure an infinite number of stress cycles. back to top Fiber The characteristic of wrought metal that indicates directional properties. It is revealed by etching a longitudinal section or manifested by the fibrous appearance of a fracture. back to top Fin Stock Coiled Sheet or foil in specific alloys, tempers and thickness ranges suitable for manufacture fins for heat exchanger applications. back to top Flatness For rolled products, a distortion of the surface of sheet such as a bulge or a wave, usually transverse to the direction of rolling. Often described by location across width, i.e., edge buckle, quarter buckle, center buckle, etc. back to top Flat Sheet Sheet with sheared, slit or sawed edges, which has been flattened or leveled. back to top Flow Lines Texture showing the direction of metal flow during hot or cold working. Flow lines often can be revealed by etching the surface or a section of a metal part. back to top Flow Stress The shear stress required to cause plastic deformation of solid metals. back to top Flux Dip Brazing The component is immersed in a molten salt which acts as a flux as well as a heat source for melting the clad layer. The fluxes are corrosive and all traces must be removed after brazing. (See Brazing) See United Aluminum Capabilities data for information on Brazing Sheet offered back to top FMEA Failure Mode and Effects Analysis, a component of QS 9000. back to top Foil A cold-rolled aluminum strip product that has thickness less than 0.006 inch (less than 0.20 mm in Europe). back to top Formability The relative ease with which a metal can be shaped through plastic deformation. back to top Four-High Mill Common rolling mill for reducing the thickness of aluminum sheet consisting of two large diameter work rolls which are supported by even larger back-up rolls. back to top Fretting (Fretting Corrosion) Action that results in surface damage, especially in a corrosive environment, when there is relative motion between solid surfaces in contact under pressure. Also commonly called "traffic marking". back to top Friction Gouges or Scratches A series of relatively short surface scratches variable in form and severity. Refer to Galling. back to top Full Hard Temper In non-heat treatable alloys, it is the hardest temper obtainable by hard cold rolling. back to top Galling The damaging of one or both metallic surfaces by removal of particles from localized areas due to seizure during sliding friction. Developing a condition on the rubbing surface of one or both mating parts where excessive friction between high spots results in localized welding with substantial spalling and a further roughening of the surface. back to top Gauge Commonly used to describe the thickness of aluminum sheet or coil in inches / millimeters. Not to be confused with comparative gauges such as Brown & Sharpe, US Standard, and Manufacturers sheet steel, which use a number to designate a non-corresponding thickness, IE "20 Gauge" is .032" on the Brown & Sharpe scale. back to top Gouge A gross scratch. back to top Grain (Direction of) Refers to grain fiber following the direction of rolling and parallel to edges of strip or sheets. (2) To bend across the grain is to bend at right angles to the direction of rolling. (3) To bend with the grain is to bend parallel to the direction of rolling. back to top Grain Coarsening A heat treatment that produces excessively large austenitic grains. back to top Grain Size For metals, a measure of the areas or volumes of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. Grain sizes are reported in terms of grains per unit area or volume, average diameter, or as a grain-size number derived form area measurements. Average diameter of grains in the metal under consideration, or alternatively, the number of grains per unit area. back to top HXX Temper Strain hardened temper. Applies to wrought products which are strengthened by cold-rolling or cold working. See "Aluminum Temper Designations" section of Technical Manual back to top H1X Temper Strain hardened only. See "Aluminum Temper Designations" section of Technical Manual back to top H2X Temper Strain hardened and partially annealed. See "Aluminum Temper Designations" section of Technical Manual back to top H3X Temper Strain hardened and stabilized See "Aluminum Temper Designations" section of Technical Manual back to top Handling Mark An area of damaged or broken surface introduced after processing. Not related to the rolling direction. back to top Hair, Slitter Minute hair-like sliver along edge(s) due to shearing or slitting operation. back to top Heat Treating / Heat Treated Process of heating and cooling a metal or alloy in a controlled process to achieve desired properties. Commonly Used to refer to "T" tempering to increase strength characteristics of heat-treatable alloys. See "Heat Treatment Tempers" section of the Technical Manual. back to top Heat-Treatable Alloys Alloys in the 2XXX, 6XXX and 7XXX series can be strengthened by heat-treating. United Aluminum can offer Alloys in each of these series. See "Capabilities" back to top Herringbone Elongated alternate bright and dull markings at an angle to the rolling direction and having the appearance of a herringbone pattern. back to top Hole Void in rolled product. Typical cause is a non-metallic inclusion during rolling. back to top Holiday Region where film is absent due to non-wetting of the metal surface by the coating. back to top Hot Mill Pickup Small particles of aluminum and aluminum oxide generated in the roll bite which subsequently transfer to the rolled product. It may be distributed uniformly and/or in streaks. back to top ID Abbreviation for inside diameter of a coil. back to top Inclusion Particles of impurities (usually oxides, sulfides, silicates, etc.) that are held mechanically or are formed during the solidification or by subsequent reaction within the solid metal. back to top Inclusion, Stringer An impurity, metallic or non-metallic, which is trapped in the ingot and elongated subsequently in the direction of working. It may be revealed during working or finishing as a narrow streak parallel to the direction of working. back to top Ingot A cast block of aluminum for subsequent rolling or forging. back to top Interleaving The placing of a sheet of paper between two adjacent layers of metal to facilitate handling and shearing of rectangular sheets, or to prevent sticking or scratching. back to top Ironing Thinning the walls of deep drawn articles by reducing the clearance between punch and die. back to top ISO International Standardization Organization, a worldwide federation of national standards bodies. Some common ISO standards that are encountered in aluminum manufacturing are:      ISO 9000, ISO 9001 - comprehensive quality management system. Specific details are given in ISO 9001.      ISO 14000, ISO 14001 - environmental management guide.      ISO 16949 - a variation of ISO 9000 that is applicable to the automotive industry.      ISO 17025 - standard used for accreditation of test laboratories. back to top Isotropy See Earing back to top JIS Japanese Industrial Standard. The common standard for aluminum coiled sheet is JIS H P4000. back to top Knife Mark (also known as Cutter Mark) A continuous scratch (which may also be creased) near a slit edge, caused by sheet contacting the slitter knife. back to top Lamination An abnormal structure resulting in a separation aligned generally parallel to the worked surface of the metal. back to top Lateral Bow See Also "Camber" An edgewise curvature referring to the deviation of side edge from a straight line. See "Lateral Bow Limits" section of Technical Manual back to top Leveling / Leveled Flattening rolled metal sheet or strip by various methods, including "roller", "stretcher", "tension", or "thermal". back to top Longitudinal Bow A longitudinal curvature in the plane of a sheet. back to top Looper (also known as Parabolics and Roping) Parabolic lines or marks on the sidewalls of deep-drawn cups. A manifestation of the rolling direction of the sheet surface. The grain structure and any longitudinal scratches will show as a parabolic pattern on the sidewalls. back to top Loose Wrap A condition in a coil due to insufficient tension which creates a small void between adjacent wraps. back to top Luder Lines Surface markings resulting from localized flow which appear on some alloys after light straining. They lie approximately parallel to the direction of the applied maximum shear stress (about 45 degrees to the direction of the applied stress). back to top Machinability The relative ease of machining a metal. back to top Malleability The property that determines the ease of deforming a metal when the metal is subjected to rolling or hammering. back to top Mark Damage in the surface of the product whose name is often described by source. back to top Mark, Chatter (Roll or Leveler) Numerous intermittent lines or grooves that are usually full width and perpendicular to the rolling direction. back to top Mark, Handling Surface damage that is introduced after processing. The mark usually has no relationship to the rolling direction. back to top Mark, Inclusion Appearance of surface where actual inclusion or the void it left is observed. back to top Mark, Knife See Knife Marks (also known as Cutter Marks) back to top Mark, Roll Small repeating raised or depressed area caused by the opposite condition on a roll. The repeat distance is a function of the offending roll diameter. back to top 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. back to top Mark, Traffic Abrasion which results from relative movement between contacting metal surfaces during handling and transit. A dark color from the abrasively produced aluminum oxide is usually observed. A mirror image of a traffic mark is observed on the adjacent contacting surface. See also "fretting" back to top Mechanical Properties The properties of a material, including Tensile Strength, Yield, and elongation, typically used to assess its suitability for a particular application relative to other alloys. See "Typical Mechanical Properties" section of the Technical Manual back to top Mill Edge The edge of strip, sheet or plate in the as rolled state. Unsheared. back to top Mill Finish A surface finish produced on sheet and plate. Characteristic of the ground finish used on the rolls in fabrication. See Capabilities for available finishes. back to top Minimum Recommended Bend Radii Minimum radii expressed in terms of thickness for bending sheets and plates without fracturing in a standard press brake with air bend dies. See "Recommended Minimum Bend radii for 90-Degree Cold Forming of Sheet" in the Technical Manual section. back to top Modulus of Elasticity Ratio of stress, within proportional limit, to corresponding strain. back to top Modulus of Elasticity (tension) The ratio of stress to strain within the perfectly elastic range. back to top Mult Aluminum sheet is generally rolled at much wider widths than the finished width. The family of narrow coils that are slit from a wide coil is called a mult. Each individual narrow coil is called a cut. back to top Necking Local reduction of the cross-sectional area of metal by stretching. back to top Nick A surface or edge discontinuity in the form of a slight cut, indentation, or notch. Also referred to as "Scratch" and "Gouge". back to top Non-Ferrous Metals Metals or alloys that are free of iron or comparatively so. back to top Non Heat-Treatable Alloy The correct term for the 1XXX, the 3XXX, the 5XXX alloy classes. These alloys gain strength only through cold working and lose strength through thermal treatments. They are also called the soft or common alloys. back to top OD Abbreviation for outer diameter of a coil. back to top O Temper Annealed temper. Applies to wrought products which have been heated above the re-crystallization temperature to produce the lowest tensile condition of the alloy. See "Aluminum Temper Designations" section of Technical Manual back to top Oil Stain Stain produced by the incomplete burning of the lubricants on the surface of the sheet. Rolling subsequent to staining will change color from darker browns to lighter browns down to white. back to top Orange Peel (effect) A surface roughening (defect) encountered in forming products from metal that has a coarse grain size. It is due to uneven flow or to the appearance of the overly large grains, and may be the result of annealing at too high a temperature. back to top 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. See also "Telescoping." back to top Oxidation Exposure to atmosphere sometimes results in oxidation of the exposed surface, hence a staining or discoloration. This effect is increased with temperature increase. A reaction in which there is an increase in valence resulting from a loss of electrons. Chemical combination with oxygen to form an oxide. For aluminum, see Waterstain. back to top Pad See Cut. back to top Pancake coil Term sometimes used to describe a narrow-slit coil that is eye-to-sky. back to top Parabolics See Loopers back to top Physical Properties Properties other than mechanical properties, that pertain to the physical nature of a material such as thermal expansion, melting range, density, thermal conductivity, Electrical conductivity, reflectivity, etc. See the "Typical Physical Properties" table in the Technical Manual section back to top Pickup Small particles of oxide adhering to the surface of the aluminum sheet, usually originating from the hot-rolling operation. Adhesion of metal to punches and dies of deep-drawing tooling is also called pickup. back to top Pit (defect) A sharp depression or mark in the surface of the metal. back to top PIW Pounds Per inch of Width. See "Coil Size Calculator" section of the Technical Manual. back to top Polished Surface The finish obtained by buffing with rouge or similar fine abrasive, resulting in a high gloss or polish. back to top PPAP Production Part Approval Process, a component of QS 9000. back to top Published Tolerances A term sometimes used synonymously with "Standard" or "Commercial" tolerances. See Commercial Tolerances. back to top PVC Type of strippable plastic that is applied to protect a surface from scratching and marking. back to top QS 9000 Quality system requirements for the automotive industry. Superceded by ISO 16949 back to top Quarter Hard Applicable to strain hardened (cold worked) alloys where the degree of strain hardening is approximately 1/4 of the way between O temper and the full hard condition (HX8). See HX2 tempers. back to top Quarter Buckle Undulation (wavy region) which occurs approximately at both quarter points across the width. back to top Quenching Rapid cooling. In the heat-treating of metals, the step of cooling metals rapidly in order to obtain desired properties; most commonly accomplished by immersing the metal in oil or water. back to top Ra See Surface Roughness back to top Reflector Sheet An alclad product containing on one side a surface layer of high-purity aluminum superimposed on a core or base alloy of commercial-purity aluminum or an aluminum-manganese alloy. The high-purity coating imparts good polishing characteristics and the core gives adequate strength and formability. back to top Reroll Stock A semi finished rolled product of rectangular cross-section in coiled form suitable for further rolling. back to top Rockwell Hardness (Test) A standard method for measuring the hardness of metals. The hardness is expressed as a number related to the depth of residual penetration of a steel ball or diamond cone (brale) after a minor load of 10 kilograms has been applied to hold the penetrator in position. This residual penetration is automatically registered on a dial when the major load is removed from the penetrator. Various dial readings combined with different major loads, five scales designated by letters varying from A to H; the B and C scales are most commonly in use. back to top Roll Forming An operation used in forming sheet by passing between rolls of definite settings that bend the sheet progressively into the desired shape. back to top Roll Chatter Numerous intermittent lines or grooves that are usually full width and perpendicular to the rolling direction. back to top Roll Mark A raised area formed during rolling by the imprint of a depression in a roll. back to top Roll Pickup Small particles of aluminum and aluminum oxide generated in the roll bite which subsequently transfer to the rolled product. It may be distributed uniformly and/or in streaks. back to top Rolled-In Scratch A scratch that occurs during the fabricating process and is subsequently rolled over. back to top Rolling Reducing the cross-sectional area of metal stock through the use of rotating rolls. A term applied to the operation of shaping and reducing metal in thickness by passing it between rolls which compress, shape and lengthen it following the roll pattern. back to top Rolling Direction (in rolled metal) The direction, in the plane of the sheet, perpendicular to the axes of the rolls during rolling. back to top Roping See Loopers back to top Rz See Surface Roughness back to top SAE Abbreviation for Society of Automotive Engineers. back to top Scratch A sharp linear indentation in the surface of the metal. back to top Scratch, Friction A scratch caused by relative motion between two contacting surfaces. back to top Scratch, Handling A more severe form of rub mark, created by other than processing. back to top Scratch, Oscillation Minor indentations at an angle to the rolling direction that result from coil oscillation during unwinding or rewinding. back to top Scratch, Rolled-In A scratch which is subsequently rolled. back to top Scratch, Tension A short longitudinal indentation parallel to the rolling direction. back to top Sendzimir Mill (Z Mill) A mill having two work rolls of 1 to 2 1/2-in diameter each, backed up by two rolls twice that diameter and each of these backed up by bearings on a shaft mounted eccentrically so that rotating it increases the pressure between bearings and backup rolls. See Picture back to top Shear Strength The stress required to produce fracture in the plane of cross section, the conditions of loading being such that the directions of force and of resistance are parallel and opposite although their paths are offset a specified minimum amount. back to top Sheet A flat-rolled metal product of some maximum thickness and minimum width arbitrarily dependent on the type of metal. Sheet is thinner than plate. Varieties include Alclad, Anodizing, Clad, Coiled, Flat, painted, etc) back to top Slit Edges The edges of sheet or strip metal resulting from cutting to width by rotary slitters. back to top Slitting A high-speed method of cutting sheet in coiled form to narrower width coils. See Picture back to top Slitter Hair Minute hair-like silver along edge(s) due to shearing or slitting operation. back to top Sliver (defect) Loose metal piece rolled down onto the surface of the metal during the rolling operations. back to top Smut A dark film of debris, sometimes covering large areas, deposited on the sheet during rolling. Also referred to as "Smudge". back to top Solution Heat Treatment A heat treatment in which an alloy is heated to a suitable temperature, held at that temperature long enough to cause one or more constituents to enter into solid solution, and then cooled rapidly enough to hold these constituents in solution. back to top Stain, Oil Surface discoloration which may vary from dark to brown to white and is produced during thermal treatment by incomplete evaporation and/or oxidation of lubricants on the surface. back to top Stain, Water (See Water Stain) Superficial oxidation of the surface with a water film, in the absence of circulating air, held between closely adjacent metal surfaces. See the "Waterstain and its Prevention" section of the Technical Manual. back to top Stamping A term used to refer to various press forming operations in coining, embossing, blanking, and pressing. back to top Strain A measure of the relative change in the size of a body. Linear strain is the change per unit length of a linear dimension. True (or natural) strain is the natural logarithm of the ratio of the length at the moment of observation to the original gauge length. Shearing strain is the change in angle (expressed in radians) between two reference lines originally at right angles. When the term is used alone, it usually refers to linear strain in the direction of the applied stress. back to top Stress Force per unit of area. Stress is normally calculated on the basis of the original cross-sectional dimensions. There are three kinds of stresses: tensile, compressive, and shear. back to top Stress-Rupture Test A tension test performed at constant temperature, the load being held at such a level as to cause rupture. back to top Stretch Forming A process of forming panels and cowls of large curvature by stretching sheet over a form of the desired shape. This method is more rapid than hammering and beating. back to top Stretcher Leveling A method of making metal sheet or strip flat by stretching. back to top Strip A sheet of metal whose length is many times its width. Also called coil, coiled strip, rolls, or bands. back to top Structure The arrangement of parts; in crystals, especially, the shape and dimension of the until cell, and the number, kinds and positions of the atoms within it. back to top Substrate The layer of metal underlying a coating, regardless of whether the layer is base metal. back to top Surface Roughness The surface texture measured using a stylus instrument across the rolling direction. The most common parameters are:      Ra - Arithmetic Average Roughness measures the height of irregularities from the mean line within the sampling length. This is the      universally recognized and most common parameter for surface roughness.      Rq - Root Mean Square (RMS) measures the average height of irregularities from the mean line using a different formula to Ra.      Once a common method, it is now seldom used.      Ry - Maximum Peak-to-Valley Height is sensitive to high peaks and deep scratches.      Rz (ISO) - Ten-Point Height is the average distance between the five highest peaks and five deepest valleys measured from a      reference line. back to top Tandem Mill Arrangement of rolling mills, in direct line, allowing the metal to pass from one set of rolls into the next. back to top Telescoping Transverse slipping of successive layers of a coil so that the edge of the coil is conical rather than flat. back to top Temper The condition of an alloy produced by mechanical and/or thermal treatment, and characterized by certain mechanical properties and structure. See also "Temper Designations" section of the Technical Manual back to top Tensile Strength Also called "ultimate strength". Breaking strength of a material when subjected to a stretching force. Usually measured by placing a standard test piece in the jaws of a tensile machine, gradually separating the jaws, and measuring the stretching force necessary to break the test piece. Tensile strength is commonly expressed as pounds (or tons) per square inch of original cross section. back to top Thickness See Gauge back to top Tolerance Allowable deviation from a nominal or specified dimension. The term "commercial tolerance" generally refers to those allowable tolerances published by the Aluminum Association. See Thickness and Width tolerances section of Technical Manual back to top Traffic Marks Abrasions resulting from relative movement between contacting metal surfaces during transit. These abrasions are usually dark in appearance due to the presence of aluminum and aluminum oxide fines produced by the abrasive action. back to top Transverse Bow Curvature across the width of sheet or coil. back to top Transverse Direction A direction perpendicular to the direction of working or rolling. back to top Ultimate Strength See Tensile Strength back to top Ultimate Tensile Strength (UTS) Another common term to describe mechanical strength. This metal property is expressed in thousands of pounds per square inch and denotes how much stress can be gradually applied to the metal before it fractures. Tensile testing is done by pulling two ends of a test sample in opposite directions under a constantly increasing force, subjecting the product to stress. The stress is measured until the product is pulled in two. The measurement at the exact time of fracture is the material's ultimate tensile strength. back to top Vacuum Brazing Components are heated in a high vacuum, completely free of oxygen. The clad alloy must contain magnesium as an alloying addition. At the brazing temperature, the heat and vacuum causes the magnesium to "boil" out of the molten metal thereby breaking up the brittle oxide skin into small, harmless shards. (See Brazing) See United Aluminum Capabilities data for information on Brazing Sheet offered back to top Water Stain White, chalky patches formed after aluminum comes in contact with water or condensation. See "Waterstain and its Prevention" in the Technical Manual section. back to top Wavy Not flat. A slight wave following the direction of rolling and beyond the standard limitation for flatness. back to top Wavy Edge A rippling departure of an edge from flat. back to top Weldability Suitability of a metal for welding under specific conditions. back to top Workability The characteristic or group of characteristics that determines the ease of forming a metal into desired shapes. back to top Wrought Product Products which began as raw material castings and are mechanically worked by processes such as rolling, extruding, forging, etc. back to top Yield Point The first stress in a material, usually less than the maximum attainable stress, at which an increase in strain occurs without an increase in stress. Only certain metals exhibit a yield point. If there is a decrease in stress after yielding, a distinction may be made between upper and lower yield points. back to top Yield Strength (also known as Proof Stress) A property of the material that describes the stress at which the material exhibits a specified permanent set. That is the point at which it will not spring back to its original length when stress on the material is relieved. For aluminum the yield strength is usually measured at the point where the stress applied to the material causes a 0.2% (of the gauge length) permanent set. back to top Z-Mill "Z Mill" or Sendzimir mill. A mill having two work rolls of 1 to 2 1/2-in diameter. each, backed up by two rolls twice that diameter and each of these backed up by bearings on a shaft mounted eccentrically so that rotating it increases the pressure between bearings and backup rolls. See Picture back to top

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