What Do Wrought Aluminum Temper Designations Mean?

A wrought aluminum-alloy temper designation follows the alloy number after a hyphen. It consists of a basic temper letter and one or more digits. The basic letters F, O, H, W, and T are defined below; subsequent digits identify subdivisions of the basic temper.

International Wrought Aluminum Temper Designations

H Temper Subdivisions

H is normally followed by two or more digits. The first digit means:

• H1: Strain hardened only.
• H2: Strain hardened and partially annealed.
• H3: Strain hardened and stabilized; applicable only to alloys that gradually soften through room-temperature aging after strain hardening.
• H4: Strain hardened and lacquered or painted.

T Temper Subdivisions

The first digit after T identifies the basic treatment:

1. T1: Cooled from an elevated-temperature forming process and naturally aged.
2. T2: Cooled from an elevated-temperature forming process, cold worked for increased strength, and naturally aged.
3. T3: Solution heat-treated, cold worked for increased strength, and naturally aged.
4. T4: Solution heat-treated and naturally aged without subsequent cold working.
5. T5: Cooled from an elevated-temperature forming process and artificially aged without cold working.
6. T6: Solution heat-treated and artificially aged without subsequent cold working.
7. T7: Solution heat-treated and overaged to a stabilized condition.
8. T8: Solution heat-treated, cold worked for increased strength, and artificially aged.
9. T9: Solution heat-treated, artificially aged, and then cold worked for increased strength.
10. T10: Cooled from an elevated-temperature forming process, cold worked for increased strength, and artificially aged.