Material Description. This specification covers the chemical composition, mechanical properties, surface quality, and structural integrity requirements of aluminum alloy hollow and semi-hollow extruded profiles produced from welding chamber (i.e., spider, porthole, or bridge) dies, solid profiles, solid round bars, and flat sheets. Refer to the Aluminum Association Aluminum Standards and Data Manual - Metric International System of Units (SI) and/or EN 755-1 for definitions of hollow, semi-hollow and solid aluminum extrusions.

Aluminum extrusions may be supplied in straight as-extruded lengths, or bent to meet desired part shape. Secondary forming operations (i.e., formation of crush initiators, flats, flanges) shall be performed before artificial aging heat treatment. For round aluminum alloy extruded tubing intended for hydroformed components, refer to GMW16866 "Hydroformed Extruded Aluminum Mechanical Tubing and Components".

The aluminum extrusion alloy and temper designations contained in this specification shall include aluminum alloys with temper mechanical property limits documented in a regional national standard - Aluminum Association (AA), European Standard (EN), ASTM International (ASTM), Japanese Industrial Standards (JIS). In this specification, aluminum extrusion alloy and temper designations that conform to regional national standards shall be designated as standard grades.

Aluminum extrusions with modified alloys and/or tempers that deviate from regional national standards shall be designated as non-standard grades. Aluminum extrusion alloys with chemical composition limits that do not conform to regional national standard chemical composition limits shall be designated as proprietary chemical composition grades. Non-standard and proprietary composition grades are divided into two categories: minimum yield strength based grades and nominal yield strength based grades. Nominal yield strength based grades are applicable to bumper system components known as crush cans, crash boxes or danner boxes.

Material Identification. This specification shall be referenced in engineering math data files or engineering drawing material specifications. The material specification shall consist of the General Motors Worldwide (GMW) specification number, the materials type, non-ferrous metal type, alloy designation, the temper designation and minimum or nominal yield strength. See Section 8 "Coding System" for further explanation.

Symbols. A₅₀, 5D, 5.65(S_o)^0.5, A, A5, ±.

Typical Applications. Typical applications include body, closure, exterior and chassis structural applications. Refer to GM Materials Engineering or the Global Preferred Materials Catalog for selection of appropriate extrusion materials for specific applications.