“H” temper-non-heat-treatable alloys / strain-hardened

H14 – Strain hardened (cold worked) without thermal treatment and 1/2 hard.

H22 – Strain hardened and partially annealed, 1/4 hard.

H32 – Strain hardened and stabilized by low temperature heating, 1/4 hard.

H34 – Strain hardened and stabilized by low temperature heating, 1/2 hard.

H111 – Applies to products that are strain-hardened less than the amount required for a controlled H11 temper.

H112 – Applies to products which acquire some temper from shaping processes not having special control over the amount of strain-hardening or thermal treatment, but for which there are mechanical property limits

H116 – Applies to products manufactured from alloys in the 5xxx series, for which the magnesium content is 3% nominal or more. Products are normally strain hardened at the last operation to specified stable tensile property limits and meet specified levels of corrosion-resistance in accelerated type corrosion tests. They are suitable for continuous service at temperatures no greater than 150°F (66°C). Corrosion tests include inter-granular and exfoliation.

“O” Temper (Annealed Temper)

Annealing is a process of heating metal past a critical temperature whereby the material is relieved of the internal stresses from production or fabrication.  It is the lowest temper available (the most easily bent)

“T” temper-heat-treatable-alloys/thermally treated

T6 – Solution heat-treated and artificially aged. A stable temper.

T52 – Stress-relieved by compressing. Applies to products that are stress-relieved by compressing after solution heat-treatment, to produce a permanent set of 1 to 5 percent.

T651 – Solution heat-treated, stress-relieved by stretching and artificially aged. Equivalent to T6 and applies to plate and rolled bar except 2219

T6511 – Solution heat-treated, stress-relieved by stretching and artificially aged with minor straightening. Equivalent to T6 and applies to extruded rod, bar and shapes except 2024.