Tempers for Non-Heat Treatable Alloys

The initial strength of alloys in this group depends upon the hardening effects of elements such as manganese, silicon, iron, and magnesium, singly or in various combinations.  The non-heat treatable alloys are usually designated, therefore, in the 1000, 3000, 4000, or 5000 series.  Since these alloys are work-hardenable, further strengthening is made possible by various degrees of cold working, denoted by the "H" series of tempers.

H1 - strain-hardened only.  Applies to products which are cold-worked to obtain the desired strength without supplementary thermal treatment.  The number following this designation indicates the degree of strain-hardening.

H2 - strain-hardened and partially annealed.  Applies to products which are strain-hardened more than the desired final amount and then reduced in strength to the desired level by partial annealing.

H3 - strain-hardened and stabilized.  Applies to products which are strain-hardened and whose mechanical properties are stabilized by a low-temperature thermal treatment which results in slightly lower tensile strength and improved ductibility.

Tempers in common alloys (non-treatable) are as follows:

Hardness             Designation

Soft                        0

¼ Hard                  H12 or H32

½ Hard                  H14 or H34

- Andy Hubbard