Temper is a measure of a metal's resistence to bending or kinking. It does not refer to how hard the metal is. Low temper, such as H-1 (also referred to as “1/8 Hard”), indicates a tendency to bend or kink permanently when subjected to very little force. High temper,such as H-8 or “Full Hard”, indicates a tendency to spring back upon bending.
The letters that appear after each alloy number refer to the “temper” of the alloy itself and are independent of the alloy. This means that a single alloy can be available in a variety of tempers and a variety of alloys can be available in the same temper.
This letter indicates that there has been no effort to control the temper of the material - you receive it “as is”.
Annealing is a process of heating up metal past a critical tempurature whereby the material is relieved of the internal stresses from production or fabrication. It is the lowest temper available (the most easily bent).
This letter refers to metal that has undergone a specific procedure to produce a temper for a particular batch of metal in order to comply with some specific need of the customer.
This letter designates a process of stretching or compressing in order to impart a particular temper.
H_1 | 1/8 hard | ||
H_2 | 1/4 hard | ||
H_3 | 3/8 hard | ||
H_4 | 1/2 hard | ||
H_5 | 5/8 hard | ||
H_6 | 3/4 hard | ||
H_7 | 7/8 hard | ||
H_8 | Full hard |
These tempers are imparted by heating, quenching, or cooling in a controlled way.
T1 | Cooled after being shaped to its final dimensions during a process involving a lot of heat (such as extrusion), then naturally aged to a stable condition. | ||
T2 | Cooled after being shaped to its final dimensions during a process involving a lot of heat (such as extrusion), then cold worked. | ||
T3 | Solution heat treated, cold worked and naturally aged to a stable condition. | ||
T4 | Solution heat treated and naturally aged to a stable condition | ||
T5 | Cooled after being shaped to its final dimensions during a process involving a lot of heat (such as extrusion), then artificially aged. T5 is T1 that has been artificially aged. | ||
T6 | Solution heat treated and artificially aged to a stable condition. T6 is T4 that has been artificially aged. | ||
T7 | Solution heat treated and naturally aged past the point of a stable condition. This process provides control of some special characteristics. | ||
T8 | Solution heat treated, cold worked and artificially aged. T8 is T3 that has been artificially aged. | ||
T9 | Solution heat treated, artificially aged and cold worked A stable temper T9 is T6 that has been cold worked. | ||
T10 | Cooled after being shaped to its final dimensions during a process involving a lot of heat (such as extrusion), then cold worked and artificially aged. T10 is T2 that has been artificially aged. |