The temper or heat treatment process involves subjecting the aluminum to heating and cooling in a controlled environment. This process adjusts both the mechanical properties and internal structure of the aluminum alloy.

As the user, it is important to recognize the temper designations and the impacts that subsequent processes can have on the product.

Aluminum products have both alloy and temper designations. Alloy designations are given in the form of four-digit numbers as an identification of the chemical composition of the alloy. As an addition to the alloy designation, temper designations are in alphanumerical form.

By looking at the temper designation, one can determine the treatment process used to achieve the product.

The tempers for 2024 aluminum include T3, T3510, T3511, T8, T8510, T8511, and O, and some tempers’ characteristics are as indicated in the table below:

2024 Aluminum Temper Description
O No heat treatment
T3 Solution heat treated

Strain hardened

Aged naturally
T3511 Solution heat treated

Stress relieved

Aged naturally
T8 Solution heat treated

Strain hardened

Aged artificially
T8511 Solution heat-treated

Stress relieved

Aged artificially