Aluminum alloys are commonly used in various industries due to their lightweight, corrosion resistance, and excellent mechanical properties. The temper designation system is used to classify different states or conditions of aluminum alloys, indicating their mechanical properties after specific heat treatments. The temper designation is usually appended to the alloy designation as a suffix.

Here are some commonly used aluminum alloy tempers:

  1. F: As-fabricated
    • Applies to alloys that have not undergone any deliberate heat treatment after forming.
    • The mechanical properties are determined by the alloy composition and the forming process.
  2. O: Annealed
    • The alloy is annealed to relieve internal stresses and improve workability.
    • This temper is characterized by a low strength but high ductility.
  3. H: Strain Hardened (Wrought Alloys)
    • H1x: Strain hardened only.
    • H2x: Strain hardened and then partially annealed.
    • H3x: Strain hardened and then stabilized.
    • The numeric value indicates the degree of strain hardening, with higher numbers representing higher levels of hardness and strength.
  4. T: Thermally Treated (Heat Treatable Alloys)
    • T1x: Solution heat treated and then artificially aged.
    • T2x: Solution heat treated and then cold worked.
    • T3x: Solution heat treated, cold worked, and then naturally aged.
    • T4x: Solution heat treated and then naturally aged.
    • T5x: Artificially aged only.
    • T6x: Solution heat treated and then artificially aged.
    • T7x: Solution heat treated, then stabilized, and then artificially aged.
    • T8x: Solution heat treated, cold worked, and then artificially aged.
    • The numeric value indicates the type and duration of heat treatment, with higher numbers representing higher levels of strength.
  5. W: Solution Heat Treated (Cast Alloys)
    • The alloy is solution heat treated to improve its mechanical properties.

These are just a few examples of the many temper designations used for aluminum alloys. The specific temper designation for a particular alloy depends on its composition, intended application, and desired mechanical properties.