Hxy ñ Subdivision of strain-hardened tempers (Topic: 10204)

The second digit (y) following the letter H indicates the final degree of strain-hardening, as identified by the minimum value of the ultimate tensile strength.

The digit 8 is used for the hardest temper normally produced. The minimum tensile strength of the temper Hx8 may be determined from the table below. It is based on the minimum tensile strength of the alloy in the annealed temper.

Tempers between O (annealed) and Hx8 are designated by the digit 1 to 7.

The digit 4 designates tempers whose ultimate tensile strength is approximately midway between that of the O temper and that of the Hx8 temper.

The digit 2 designates tempers whose ultimate tensile strength is approximately midway between that of the O temper and that of the Hx4 temper.

The digit 6 designates tempers whose ultimate tensile strength is approximately midway between that of the Hx4 temper and that of the Hx8 temper.

Table

Min tensile strength Increase in tensile strength

in annealed temper to Hx8 temper

MPa MPa

ñ40 55

45ñ60 65

65ñ80 75

85ñ100 85

105ñ120 90

125ñ160 95

165ñ200 100

205ñ240 105

245ñ280 110

285ñ320 115

325ñ 120