Glossary of Terms
ALUMINUM INDUSTRY DEFINITIONS
A
AMS - Abbreviation for Aerospace Material Specification.
ANSI - Abbreviation for American National Standards Institute.
ASME - Abbreviation for American Society of Mechanical Engineers.
ASTM - Abbreviation for American Society for Testing and Materials.
AWS - Abbreviation for American Welding Society.
Age Hardening - An aging process that results in increased strength and hardness.
Age Softening - Spontaneous decrease of strength and hardness that takes place at room temperature in certain strain-hardened alloys containing magnesium.
Aging - Precipitation from solid solution resulting in a change in properties of an alloy, usually occurring slowly at room temperature (natural aging) and more rapidly at elevated temperatures (artificial aging).
Alclad - An aluminum or aluminum-alloy coating that is metallurgically bonded to either one or both surfaces of an aluminum alloy product, and that is anodic to the alloy to which it is bonded, thus electrolytically protecting the core alloy against corrosion.
Alloy - A substance having metallic properties and composed of two or more elements of which at least one is an elemental metal.
Angularity - Conformity to, or deviation from, specified angular dimensions in the cross section of a shape or bar.
Annealing - A thermal treatment to soften metal by removal of stress resulting from cold working or by coalescing precipitates from solid solution.
Anodizing - Forming a coating on a metal surface produced by electrochemical treatment through anodic oxidation.
B
Bar - A solid wrought product that is long in relation to its cross section which is square or rectangular (excluding plate and flattened wire) with sharp or rounded corners or edges, or is a regular hexagon or octagon, and in which at least one perpendicular distance between parallel faces is 0.375 inch or greater.
Bar, Cold Finished - Bar brought to final dimensions by cold work to obtain improved surface finish and dimensional tolerances.
Billet - A hot worked semi-finished product suitable for subsequent working by such methods as rolling, forging, extruding, etc.
Blank - A piece of metal cut or formed to regular or irregular shape for subsequent processing such as by forming, bending or drawing. The piece of sheet stock cut out by blank die. It will subsequently be drawn into a cup or end shell.
Blister - A raised area on the surface of an extruded product due to subsurface gas expansion. This can occur during extrusion or thermal treatment.
Bloom - A semi-finished hot rolled product, rectangular or square in cross section, produced on a blooming mill.
Bow - Longitudinal curvature of rod, bar, profiles (shapes), and tube. Bow is measured after allowing the weight of the extrusion to minimize the deviation. Bow can be caused by a non-uniform extrusion rate across the cross section resulting in one portion of the extrusion being longer than the other or non-uniform contraction during quenching.
Brazing - Joining metals by fusion of nonferrous alloys that have melting points above 425C (800F) but lower than those of the metals being joined. This may be accomplished by means of a torch (torch brazing), in a furnace (furnace brazing), or by dipping in a molten flux bath (dip or flux brazing).
Broken Die - A deviation from the desired cross section due to the absence of a certain portion of the die used to extrude the profile (shape).
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.
Burr - A thin ridge of roughness left by a cutting operation such as slitting, trimming, shearing, blanking or sawing.
Bus Bar - A rigid electric conductor in the form of a bar.
C
CAD - Computer Aided Design
Cold Working - Plastic (i.e., permanent) deformation of metal at such temperature and rate that strain-hardening occurs.
Concavity - Curved like the inner surface of a sphere.
Concentricity - Conformance to a common center as, for example, the inner and outer walls of round tube.
Corrosion - the deterioration of a metal or chemical or electrochemical reaction with its environment.
Corrosion, Exfoliation - Corrosion that progresses approximately parallel to the metal surface, causing layers of the metal to be elevated by the formation of corrosion product.
Corrosion, Intergranular - Corrosion occurring preferentially at grain boundaries (also termed intercrystalline corrosion).
Corrosion, Pitting - Localized corrosion resulting in small pits or craters in a metal surface.
Corrosion, Stress Cracking - Failure by cracking resulting from selective directional attack caused by the simultaneous interaction of sustained tensile stress at an exposed surface with the chemical or electro-chemical effects of the surface environment. The term is often abbreviated SCC which correctly stands for stress corrosion cracking.
Corrosion, Water Stain - Superficial oxidation of the surface with a water film, in the absence of circulating air, held between closely adjacent metal surfaces.
D
Deep Drawing - Forming a deeply recessed part by forcing sheet metal to undergo plastic flow between dies, usually without substantial thinning of the sheet.
DFARS - Defense Federal Acquisition Regulation Supplement defining specific materials that must be purchased Domestically or from a Preferred Country of Manufacture. Aluminum products cannot be considered DFARS-compliant because aluminum is not classified as a “Specialty Metal” under DFARS clause 252.225-7014. Schupan Aluminum & Plastic Sales can, however, attempt to quote/supply material from a Domestic or Preferred Country of Manufacture listed in DFARS clause 225.872-1.
Die Line - A longitudinal depression or protrusion formed on the surface of drawn or extruded material. Die lines are present to some degree in all extrusions and are caused by a roughening of the die bearing.
Die Number - the number assigned to a die for identification and cataloging purposes, and which usually is assigned for the same purpose to the product produced from that die.
Drawing - (1) In forging, an operation of working metal between flat dies to reduce the cross section and increase length, (2) The process of pulling material through a die to reduce the size, change the cross section or shape, or harden the material.
E
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 (IACS), which has a resistivity of 1/58 ohm-mm2/meter at 68 degrees F and an arbitrarily designated conductivity of unity.
Electrical Resistivity - The electrical resistance of a body of unit length and unit cross-sectional area of unit weight. The value of 1/58 ohm-mm2/meter at 68 degrees F is the resistivity equivalent to the International Annealed Copper Standard for 100 percent conductivity. This means that a wire of 100 percent conductivity, 1 meter in length and 1 square millimeter in cross-sectional area would have a resistance of 0.017241 ohms at 68 degrees F.
Elongation - the percentage increase in distance between two gauge-marks that results from stressing the specimen in tension to fracture. The original gauge length is usually 2 inches for flat specimens and round specimens whose diameter is ¹⁄₂ inch, or four times the diameter for specimens where that dimension is under ¹⁄₂ inch. Elongation values depend to some extent upon size and form of the test specimen. For example, the values obtained from sheet specimens will be lower for thin sheet than for thicker sheet.
Embossing - Raising a design in relief against a surface.
Extrusion - A product formed by pushing material through a die.
Extrusion Billet - The starting stock for the extrusion operation. Extrusion billet is a solid or hollow form, commonly cylindrical and is the length charged into the extrusion press cylinder. It is usually a cast product but may be a wrought product or powder compact.
Extrusion Ingot - A cast form that is solid or hollow, usually cylindrical, suitable for extruding. See also “Fabricating Ingot.”
Extrusion Log - The starting stock for extrusion billet. Extrusion log is usually produced in lengths from which shorter extrusion billets are cut.
F
Fabricating Ingot - A cast form suitable for subsequent working by such methods as rolling, forging, extruding, etc. (“Rolling Ingot,” “Forging Ingot,” “Extrusion Ingot.”)
Fatigue - The tendency for a metal to break under conditions of repeated cyclic stressing considerably below the ultimate tensile strength.
Flatness - (1) For rolled products is 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. (2) For extrusions flatness (off contour) pertains to the deviation of a cross-section surface intended to be flat. Flatness can be affected by conditions such as die performance, thermal effects and stretching.
Foil - A rolled product rectangular in cross section of thickness less than 0.006 inch. In Europe, foil is equal to and less than 0.20 mm.
Forgeability - the term used to describe the relative workability of forging material.
Forging - A metal part worked to a predetermined shape by one or more processes such as hammering, upsetting, pressing, rolling, etc.
G
Gauge - A term previously used in referring to the thickness of a wrought product. Thickness is preferred in dimension description.
Gouge - A gross scratch See “Scratch.”
Grain Flow - The directional characteristics of the metal structure after working, revealed by etching a polished section.
Grain Size - A measure of crystal size usually reported in terms of average diameter in millimeters, grains per square millimeter, or grains per cubic millimeter.
H
Hardness - Resistance to plastic deformation, usually by indention. The term may also refer to stiffness or temper, or to resistance to scratching, abrasion or cutting. Brinell Harness: Brinell hardness of aluminum alloys is obtained by measuring the permanent impression in the material made by a ball indenter 10 millimeters in diameter after loading with a 500 kilogram-force for 15 seconds and dividing the applied load by the area of the impression. Rockwell Hardness: An indentation hardness test based on the depth of penetration of a specified penetrator into the specimen under certain arbitrarily fixed conditions.
Heat Treating - Heating and cooling a solid metal or alloy in such a way as to obtain desired conditions or properties. Commonly used as a shop term to denote the thermal treatment to increase strength. Heating for the sole purpose of hot working is excluded from the meaning of this definition.
Heat-Treatable Alloy - An alloy that may be strengthened by a suitable thermal treatment.
Homogenizing - A process whereby ingots are raised to temperatures near the solidus temperature and held at that temperature for varying lengths of time. The purposes of this process are to (1) reduce microsegregation by promoting diffusion of solute atoms within the grains of aluminum and (2) improve workability.
I
IAPD - International Association of Plastic Distributors. The trade association for plastic distributors.
Inclusion - Foreign material in the metal or impressed into the surface.
Ingot - A cast form suitable for re-melting or fabrication. See “Fabricating Ingot,” “Extrusion Ingot,” and “Rolling Ingot.”
Interleaving - The insertion of paper or application of suitable strippable coatings between layers of metal to protect from damage.
ISO - International Organization for Standards; ISO 9001 is among ISO’s most well known standards. ISO 9001 is the standard for quality management. Quality management is what an organization does to ensure that its products or services satisfy the customer’s quality requirements, and comply with any regulations applicable to those products or services. (Source: International Organization for Standardization’s “Overview of ISO 9001 and ISO 14001” presentation by Roger Frost.)
ISRI - Institute of Scrap Recycling Industry. The trade association for scrap metal processors.
L
Lamination - An internal crack or separation that is aligned parallel to the direction of major metal flow and, in the case of plate, sheet or foil, parallel to the rolled surfaces. In extrusions, it can be caused by contaminants that feed into the metal flow before it reaches the die opening or cracked billets.
Leveling - the mechanical flattening of plate, sheet or foil.
Lot, Heat Treat - Material of the same mill form, alloy, temper, section and size traceable to one heat-treat furnace load (or extrusion charge or billet in the case of press heat-treated extrusions) or, if heat treated in a continuous furnace, charged consecutively during an 8-hour period.
Lot, Inspection - (1) For non-heat treated tempers, an identifiable quantity of material of the same mill form, alloy, temper, section and size submitted for inspection at one time. (2) For heat-treated tempers, an identifiable quantity of material of the same mill form, alloy, temper, section and size traceable to a heat treat lot or lots and submitted for inspection at one time. (3) For sheet and plate, all material of the same size.
M
Mechanical Properties - Those properties of a material that are associated with elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, modulus of elasticity, tensile strength, endurance limit. These properties are often incorrectly referred to as physical properties.
MSCI - Metals Service Center Institute. The trade association for metal distributors.
N
Notch, Double Shear - An abrupt deviation from straight on a sheared edge. This offset may occur if the flat sheet or plate product is longer than the blade for the final shearing operation.
O
Ovality - Deviation from a circular periphery, usually express as the total difference found at any one cross section between the individual maximum and minimum diameters, which usually occur at or about 90 degrees to each other. Since ovality is the difference between extreme diameters, it is not expressed as plus or minus.
P
Parent Plate - A plate that has been processed to final temper as a single unit. The parent plate may subsequently be cut into two or more smaller plates to provide the required width and length.
Physical Properties - The properties, other than mechanical properties, that pertain to the physics of a material; for example, density, electrical conductivity, heat conductivity and thermal expansion.
Pipe - Tube in standardized combinations of outside diameter and wall thickness, commonly designated by “Nominal Pipe Sizes” and “ANSI Schedule Numbers.”
Pipe, Drawn - Pipe brought to the final dimensions by drawing through a pipe.
Pipe, Extruded - Pipe formed by hot extruding.
Pipe, Seamless - Extruded or drawn pipe that does not contain any line junctures resulting from the method of manufacture.
Pipe, Structural - Pipe commonly used for structural purposes
Pit - A depression in the rolled surface that is usually not visible from the opposite side.
Plate - A rolled product that is rectangular in cross section and with thickness not less than 0.250 inch with sheared or sawed edges.
Plate Circle - Circle cut from plate.
Plate, Alclad - Composite plate comprised of an aluminum alloy core having on both surfaces (if on one side only, Alclad One Side Plate) a metallurgically bonded aluminum or aluminum alloy coating that is anodic to the core, thus electrolytically protecting the core against corrosion.
PPAP - Production Part Approval Process. The process of developing a new product and approving its production processes, including dimensional conformance.
Preheating - A high temperature soaking treatment to provide a desired metallurgical structure. Homogenizing is a form of preheating. Profile, Drawn - A profile brought to final dimensions by drawing through a die.
Profile, Extruded - A profile produced by hot extruding.
Profile, Structural - A profile in certain standard alloys, tempers, sizes, and sections, such as angles, channels, H-sections, I-beams, tees, and zees commonly used for structural purposes. For channels and I-beams, there are two standards: Aluminum Association Standard and American Standard.
Q
Quenching - The controlled rapid cooling of a metal from an elevated temperature by contact with a liquid, gas or solid.
R
Refined Aluminum - Aluminum of very high purity (99.950 percent or higher) obtained by special metallurgical treatments.
Reroll Stock - A semi-finished rolled product of rectangular cross section in coiled from suitable for further rolling. Some examples are “Foil Stock” and “Sheet Stock.”
Rod - A solid wrought product that is long in relation to its circular cross section, which is not less than 0.375 inch diameter.
Rod, Alclad - Rod having on its surface a metallurgically bonded aluminum or aluminum alloy coating that is anodic to the core alloy to which it is bonded, thus electrolytically protecting the core alloy against corrosion.
Rod, Cold-Finished - Rod brought to final dimensions by cold working to obtain improved surface finish and dimensional tolerances.
Rod, Cold-Finished Extruded - Rod produced by cold working extruded rod.
Rod, cold Finished Rolled - Rod produced by cold working rolled rod.
Rod, Cold-Heating - Rod of a quality suitable for use in the manufacture of cold-headed products such as rivets and bolts.
Rod, Extruded - Rod produced by hot extruding.
ROHS - RoHS, also known as Lead-Free, stands for Restriction of Hazardous Substances. RoHS Directive 2002/95/EC restricts the use of six hazardous materials found in electrical and electronic products. All applicable products in the European Union market after July 1, 2006 must pass RoHS compliance. RoHS impacts the entire electronics industry.
Rolling Ingot - A cast form suitable for rolling. See “Fabricating Ingot.”
S
Sample - A part, portion or piece taken for purposes of inspection or testing as representative of the whole.
Scratch - (1) for rolled products, a sharp indention in the surface usually caused by a machine or during handling. (2) For extrusions, a synonym for handling mark.
Seam, Extrusion - The junction line of metal that has passed through a hollow die, separated and rejoined at the exit point. Seams are present in all extruded hollows produced from the direct extrusion process and in many cases are not visible.
Seamless - A hollow product that does not contain any junctures resulting from method of manufacture.
Shear Strength - The maximum stress that a material is capable of sustaining in shear. In practice, shear strength is considered to be the maximum average stress computed by dividing the ultimate load in the plane of shear by the original area subject to shear. Shear strength is usually determined by inserting a cylindrical specimen through round holes in three hardened steel blocks, the center of which is pulled (or pushed) between the other two so as to shear the specimen on two planes. The maximum load divided buy the combined cross- sectional area of the two planes is the shear strength.
Sheet - A rolled product that is rectangular in cross section with thickness less than 0.250 inch but not less than 0.006 inch and with slit, sheared or sawed edges.
Sheet, Alclad - Composite sheet comprised of an aluminum alloy core having on both surfaces (if one side only, Alclad One Side sheet) a metalurgically bonded aluminum or aluminum alloy coating that is anodic to the core, thus electrolytically protecting the core against corrosion.
Sheet, Anodizing - Sheet with metallurgical characteristics and surface quality suitable for the development of protective and decorative films by anodic oxidation processes.
Sheet, Coiled Cut-to-Length - Sheet cut to specified length from coils and which has a lesser degree of flatness than flat sheet. Sheet, Flat - Sheet with sheared slit or sawed edges, with has been flattened or leveled.
Sheet, Mill Finish (MF) - Sheet having a non-uniform finish that may vary from sheet-to-sheet and within a sheet, and may not be entirely free from stains and oil.
Sheet, Painted - Sheet, one or both sides of which has a factory- applied point coating of controlled thickness.
Solidworks - A type of 3D computer aided design software.
Squareness - Characteristics of having adjacent sides or planes meeting at 90 degrees.
Straightness - the absence of divergence from a right (straight) line in the direction of measurement.
Strain - A measure of the change in size or shape of a body under stress, referred to its original size or shape. Tensile or compressive strain is the change, due to force, per unity of length in an original linear dimension in the direction of the force. It is usually measured as the change (in inches) per inch of length.
Stress - Force per unit of area. Stress is normally calculated on the basis of the original cross-sectional dimensions. The three kinds of stresses are tensile, compressive and shear.
Stress Relieving - The reduction of the effects of internal residual stresses by thermal or mechanical means.
T
Telescoping - Lateral stacking, primarily in one direction, of warps in a coil so that the edges of the coil are conical rather than flat. Improper alignment of roll over which the metal passes before rewinding is a typical cause.
Temper - The condition produced by either mechanical or thermal treatment, or both, and characterized by a certain structure and mechanical properties.
Tensile Strength - In tensile testing, the ratio of maximum load to original cross-sectional area. Also called “Ultimate Strength.”
Tolerance - The allowable deviation from a nominal or specified dimension.
Tooling Plate - A cast or rolled product of rectangular cross section of thickness 0.250 inch or greater, and with edges either as-cast, sheared or sawed, with internal stress levels controlled to achieve maximum stability for machining purposes in tool and jig applications.
Tread Plate - Sheet or plate having a raised figured pattern on one surface to provide improved traction.
Tube - a hollow wrought product that is long in relation to its cross section, which is symmetrical and is round, a regular hexagon or octagon, elliptical, or square or rectangular with sharp or rounded corners, and that has uniform wall thickness except as affected by corner radii.
Tube, Arc-Welded - Tube made from sheet or plate butt welded by either gas-tungsten or gas-metal arc-welding method, with or without the use of filler metal.
Tube Bloom - This term is not recommended. The term “Tube Stock” is preferred.
Tube Stock - A semi-finished tube suitable for the production of drawn tube.
Tube, Alclad - Composite tube composed of an aluminum alloy core having on either the inside or outside surface a metallurgically bonded aluminum or aluminum alloy coating that is anodic to the core, thus electrolytically protecting the core against corrosion.
Tube, Brazed - A tube produced by forming and seam-brazing sheet.
Tube, Butt-Welded - A welded tube, the seam of which is formed by positioning one edge of the sheet against the other for welding.
Tube, Drawn - A tube brought to final dimensions by cold drawing through a die. (Note: This product may be produced from either seamless or non-seamless extruded stock or from welded stock.)
Tube, Extruded - A tube formed by hot extruding. (Note: This product may be either seamless or non-seamless.)
Tube, Seamless - A tube that does not contain any line junctures (metallurgical welds) resulting from the method of manufacture. (Note: this product may be produced by die and mandrel or by hot piercer processes.)
Tube, Structural - Tube commonly used for structural purposes.
Tube, Welded - A tube produced by forming and seam-welding sheet longitudinally.
Tubing - this term is not recommended. The term “Tube” is preferred.
Twist - (1) For rolled products, a winding departure from flatness. (2) For extrusions, a winding departure from straightness. Welding - Joining two or more pieces of aluminum by applying heat or pressure, or both, with or without filler metal to produce a localized union through fusion or recrystallization across the interface. (In cold welding, it is a solid state welding process in which pressure is used at room temperature to produce coalescence of metals with substantial deformation at the weld.)
W
Welding Rod - A rolled, extruded, or cast round filler metal for use in joining by welding.
Welding Wire - Wire for use as filler metal in joining by welding.
Wire - A solid wrought product that is long in relation to its cross section, which is square or rectangular with sharp or rounded corners or edges, or is round, hexagonal, or octagonal, and whose diameter or greatest perpendicular distance between parallel face is less than 0.375 inch.
Wire, Alclad - A composite wire product comprised of an aluminum- alloy wire having on its surface a metallurgically bonded aluminum or aluminum-alloy coating that is anodic to the alloy to which it is bonded, thus electrolytically protecting the core alloy against corrosion.
Workability - The relative ease with which an alloy may be formed by rolling, extruding, forging, etc.
Wrought Product - a product that has been subjected to mechanical working by such processes as rolling, extruding, forging, etc.
Y
Yield Strength - the stress at which a material exhibits a specified permanent set. The offset used for aluminum and its alloys is 0.2 percent of gauge length. For aluminum alloys, the yield strengths in tension and compression are approximately equal.