Glossary Terms



Substance having metallic properties and composed of two or more elements, so combined that they cannot readily be separated by physical means.

Alloying Element

Metallic or non-metallic element which is controlled within specific upper and lower limits for the purpose of giving aluminum alloy certain special properties.

Aluminum Alloy

Aluminum which contains alloying elements, where aluminum predominates by mass over each of the other elements and where the aluminum content is not greater than 99.00%

Note: North American Aluminum Alloy Designations are managed by the Aluminum Association and are presented in 4-digit format, with the first digit designating the basic alloy chemistry and characteristics, e.g., 6xxx series alloys are predominately alloyed with Magnesium and Silicon, are heat-treatable, and are the most common alloys used for the extrusion. The subsequent 3 digits identify the specific chemistry – alloying elements and ranges – hence the alloy’s performance characteristics. For example, 6082, a higher strength alloy, is specified with the following chemistry:

Element Weight Percentage (%)
Aluminum 95.2 to 98.3
Chromium 0.25% max 
Copper 0.1% max 
Iron 0.5% max 
Magnesium 0.6 to 1.2%
Mangenese  0.4 to 1.0%
Silicon 0.7 to 1.3%
Titanium 0.1% max 
Zinc 0.2% max 
Residuals 0.15% max 







Given the range in permitted alloying elements, it should be apparent that there can be a number of 6082 variants, with slight differences in performance.

Heat Treatable Alloy 

Alloy which can be strengthened by suitable thermal treatment, e.g., 2xxx, 6xxx and 7xxx series extrusion alloys.

Non-Heat-Treatable Alloy

Alloy which is primarily strengthened only by working and not by thermal treatment, e.g. extrusion alloys in the 1xxx, 3xxx and 5xxx series.

Primary Aluminum

Unalloyed aluminum produced from alumina, typically by electrolysis, and with an aluminum content of 99.7%.

Unalloyed Aluminum 

Aluminum without alloying elements where the minimum aluminum content is specified to be greater than 99.00%.

Wrought Alloy

Alloy primarily intended for the production of wrought products by hot and/or cold working.



Cast product intended and suitable for remelting or forming by hot or cold working.

Primary Aluminum Ingo

Ingot of unalloyed or alloyed aluminum cast from primary aluminum.

Recycled Aluminum Ingot

Aluminum ingot obtained by recycling scrap.

Extrusion Ingot

Ingot intended and suitable for extruding, typically of solid circular cross-section, sometimes with a central hollow or a flattened cross-section. May also be referred to as an Extrusion Log.

Extrusion Log

Extrusion ingot not cut to length.

Extrusion Billet 

Extrusion ingot cut to length.


A forming process to transform aluminum ingots or billets into a semi-finished shape. Typical aluminum semi-fabrication processes include rolling, extrusion, forging and casting. Products of a semi-fabrication process often require further manufacturing – fabrication, finishing, and assembly – to turn into a final product for end use.

Semi-Finished (Semi-Fabricated) Product 

Product that has undergone some processing and is supplied for further processing before it is ready to use. Semi-finished product may be surface treated and/or coated.

Note: Semi-finished products include wrought products and castings. It does not include ingots and billets.

Unwrought Product 

Product obtained by casting without further hot or cold working, e.g., ingots for rolling, ingots for extruding, ingots for remelting, cast plate or castings.

Wrought Product 

Product that has been subjected to hot and/or cold working.



Process by which a billet in a container is forced under pressure through an aperture of a die.

Extrusion Press 

Machine consisting essentially of a container, a ram or other pressure-applying device, and a die, used for extrusion.

Extruded Profile 

Profile brought to final dimension by the process of extrusion.

Solid Profile 

Profile in which the cross-section does not include any enclosed void.

Hollow Profile 

Profile in which the cross-section completely encloses one or more voids.

Semi-Hollow Profile 

Solid profile, any part of whose cross-section is a partially enclosed void, the area of which is substantially greater than the square width of the gap.


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 a rectangular hexagon or octagon, typically supplied in straight length. Typically produced via extrusion.


Hollow wrought product of uniform cross-section with only one enclosed void and with a uniform wall thickness, supplied in straight lengths or in coiled form; cross-sections are in the shape of circles, ovals, squares, rectangles, equilateral triangles or regular polygons and can have corners rounded, provided the inner and outer cross-sections are concentric and have the same form and orientation. Often produced via extrusion.

Extruded Shape 

An extruded profile other than a bar or a tube.


Correcting operation of an extruded product, to fulfill the requirements concerning tolerances and dimensions. Typically accomplished during the stretching process but may also be accomplished (or further refined) in a secondary operation.


Cooling a metal from an elevated temperature by contact with a solid, liquid or gas, at a rate rapid enough to retain most or all of the soluble constituents in a solid solution. Often key to achieving desired physical properties.


Treatment of a metal aiming at a change in its properties by precipitation of intermetallic phases from supersaturated solid solution.

Note: Ageing can be a treatment at room temperature (natural ageing) or a thermal treatment (artificial ageing in an ageing oven).


Condition of the metal produced by the ageing process, typically characterized by a certain structure and specified properties.



The process by which semi-fabricated aluminum is transformed into a component or finished product. Typical aluminum fabrication techniques include precision cutting, trimming, stamping, bending and joining with other materials, etc. Examples of fabrication for building products include window manufacturing – including the preparation of components for assembly – with extruded aluminum shapes and profiles.

Anodized Extrusion 

Extrusion with an anodic layer, produced by an electrolytic oxidation process in the which the metal surface layer is converted to an oxide layer having protective, decorative or functional properties.


Process in which a coating material is applied on a metallic substrate. Included cleaning and chemical pre-treatment.

Note 1: This term covers a one-side or two-side, single or multiple application of liquid or powder coating materials which are subsequently cured.

Note 2: This term also covers laminating with plastic films.

Mill Finish Extrusion

Extruded profile having a finish defined by the actual extrusion operation, without further specification from a customer or a standard.

Note: The finish of mill finish extrusions can vary from part to part.


Aluminum Scrap

Raw material, destined for trade and industry, mainly consisting of aluminum resulting from the collection and/or recovery of metal that arises as waste at various production stages; or products after use to be used for the production of wrought and cast alloys and for other production processes.

Post-Consumer Material 

“Material generated by households or by commercial, industrial and institutional facilities in their role as end-users of the product than can no longer be used for its intended purpose. This includes returns of materials from the distribution chain” (ISO 14021).

Pre-Consumer Material 

“Material diverted from the waste stream during the manufacturing process. Excluded is the reutilization of materials such as rework, regrind or scrap generated in a process capable of being reclaimed within the same process that generated it” (ISO 14021).

Recycled Content 

Often used as an indicator for marketing products and is defined by ISO 14021 as “the proportion, by mass, of recycled material in a product or packaging. Only pre-consumer and post-consumer materials shall be considered as recycled content” (ISO 14021).

Recycling Rate 

The percentage reflecting the amount of material recycled relative to the amount of material generated (U.S. EPA: measuring recycling: a guide for state and local governments), e.g., in the building and construction context, it would be the percentage of the total amount of aluminum contained in a building that was recycled – at the end of life.

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