With the growth of aluminum within the metal fabrication industry, and its acceptance as an excellent alternative to steel for many applications, there are demanding requirements for those involved with developing aluminum to meet specifications. To begin to understand it’s good to look a some of the many aluminum alloys available and their characteristics.<\/p>\n\n\n\n
WROUGHT ALUMINUM ALLOY DESIGNATION SYSTEM<\/strong><\/p>\n\n\n\n The second and third digits (xXX<\/strong>.x) are arbitrary numbers given to identify a specific alloy in the series. The number following the decimal point indicates whether the alloy is a casting (.0) or an ingot (.1 or .2). A capital letter prefix indicates a modification to a specific alloy.<\/p>\n\n\n\n Understanding tempering is also important. Here is a table to help: <\/p>\n\n\n\n THE BASIC TEMPER DESIGNATIONS<\/strong><\/p>\n\n\n\nAlloy Series<\/strong><\/td> Principal Alloying Element<\/strong><\/td><\/tr> 1xxx<\/em><\/strong><\/td> 99.000% Minimum Aluminum<\/td><\/tr> 2xxx<\/em><\/strong><\/td> Copper<\/td><\/tr> 3xxx<\/em><\/strong><\/td> Manganese<\/td><\/tr> 4xxx<\/em><\/strong><\/td> Silicon<\/td><\/tr> 5xxx<\/em><\/strong><\/td> Magnesium<\/td><\/tr> 6xxx<\/em><\/strong><\/td> Magnesium and Silicon<\/td><\/tr> 7xxx<\/em><\/strong><\/td> Zinc<\/td><\/tr> 8xxx<\/em><\/strong><\/td> Other Elements<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Letter<\/strong><\/td> Meaning<\/strong><\/td><\/tr> F<\/strong><\/td> As fabricated \u2013 Applies to products of a forming process in which no special control over thermal or strain hardening conditions is employed<\/td><\/tr> O<\/strong><\/td> Annealed \u2013 Applies to product which has been heated to produce the lowest strength condition to improve ductility and dimensional stability<\/td><\/tr> H<\/strong><\/td> Strain Hardened \u2013 Applies to products that are strengthened through cold-working. The strain hardening may be followed by supplementary thermal treatment, which produces some reduction in strength. The \u201cH\u201d is always followed by two or more digits (see subdivisions of H temper below)<\/td><\/tr> W<\/strong><\/td> Solution Heat-Treated \u2013 An unstable temper applicable only to alloys which age spontaneously at room temperature after solution heat-treatment<\/td><\/tr> T<\/strong><\/td> Thermally Treated – To produce stable tempers other than F, O, or H. Applies to product that has been heat-treated, sometimes with supplementary strain-hardening, to produce a stable temper. The \u201cT\u201d is always followed by one or more digits (see subdivisions of T temper below)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n