The mechanical and technological characteristics of the products of aluminium alloys are determined not only by their chemical composition, but also by the production method and heat treatment. For example, cold-rolled sheet metal is stronger and tougher, but less ductile than a sheet metal of the same alloy produced by hot-rolling. The nature of such technologically contingent alloy is indicated as temper. So the temper of the alloys is the result of the whole production process, it corresponds to the resulting structure of the material and represents a set of properties after the given method of manufacture and heat treatment. For aluminium alloys, there are several tempers. There are two systems of designation:

a) numeric, b) on the basis of chemical symbols. For wrought aluminium alloys the method of designation used by the Aluminium Association (AA) in Washington, USA has been adopted in the international practice. 

The numerical designation consists of: a) letters EN indicating a European standard, b) letters AW (Aluminium Wrought, meaning wrought aluminium alloys), c) four digits of which the first digit indicates the principal alloying element (1xxx-pure aluminium Al 99.9% or more,  2xxx - copper Cu, 3xxx - manganese Mn, 4xxx - silicon Si, 5xxx - magnesium Mg, 6xxx- magnesium and silicon MgSi, 7xxx - zinc, 8xxx - other elements, 9xxx - unused series, d) indication in what temper the alloys are supplied.