The classification scheme
Temper designations indicate the effect manufacturing processes and subsequent treatments have on aluminum alloys. Most popular materials fall into one of two temper classifications: H, strain-hardened or T, thermally treated.
Other tempering procedures yield products designed F, as fabricated; O, annealed; or W, solution heat treated.
H tempers
Major classifications, where _ indicates degree
Non-heat treatable
| H1_ | Strain-hardened only |
| H2_ | Strain-hardened and partially annealed |
| H3_ | Strain-hardened and stabilized |
H temper hardness designations
Degree of hardness, where _ indicates temper classification
Non-heat treatable
| 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 (about 75% reduction after full annealing) |
| H_9 | Extra hard (limited availability) |
T tempers
Heat treatable
| T1 |
Cooled from an elevated temperature shaping process and naturally aged to a substantially stable condition
Usually associated with extruded products and limited to certain of the 6XXX series alloys
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| T2 |
Cooled from an elevated temperature shaping process, cold worked and naturally aged to a substantially stable condition
Usually associated with cast products
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| T3 |
Solution heat treated, cold worked and naturally aged to a substantially stable condition
Working serves to increase strength
T3 is T4 that has been cold worked |
| T4 |
Solution heat treated and naturally aged to a substantially stable condition
|
| T5 |
Cooled from an elevated temperature shaping process and artificially aged
Usually associated with extruded products in certain 6XXX series alloys
T5 is T1 that has been artificially aged |
| T6 |
Solution heat treated and artificially aged
A stable temper
T6 is T4 that has been artificially aged |
| T7 |
Solution heat treated, overaged and stabilized
Alloys that are thermally overaged after solution heat treatment to carry them beyond the point of maximum strength, which provides control of some special characteristics
A stable temper |
| T8 |
Solution heat treated, cold worked and artificially aged
A stable temper
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 from an elevated temperature shaping process, cold worked and artificially aged
Usually associated with cast products
A stable temper T10 is T2 that has been artificially aged |
T temper variations
Stress-relieved tempers of wrought products, where _ indicates basic temper
T42 and T62 are special designations for products heat treated from annealed stock or wrought products heat treated by the user
| T_51 |
Products that have been stress relieved by stretching (after solution heat treatment or after cooling from an elevated temperature shaping process) as indicated
No straightening after stretching
Plate: 1.5 - 3% permanent set
Rolled or cold finished rod or bar: 1 - 3% permanent set Die or ring forgings: 1 - 5% permanent set |
| T_510 |
Extruded products and drawn tube stress relieved by stretching (after solution heat treatment or after cooling from an elevated temperature shaping process) as indicated
No straightening after stretching
Rod, bar, shapes and tube: 1 - 3% permanent set
Drawn tube: 0.5 - 3% permanent set |
| T_511 |
Extruded products and drawn tube stress relieved by stretching (after solution heat treatment or after cooling from an elevated temperature shaping process) as indicated
May receive minor straightening after stretching
Bar, shapes and tube: 1 - 3% permanent set
Drawn tube: 0.5 - 3% permanent set |
| T_52 |
Products that have been stress relieved by compressing
|
| T_54 |
Die forgings stress relieved by restriking cold
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| T42 |
Solution heat treated and naturally aged to a substantially stable condition
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| T62 |
Solution heat treated and naturally aged to a substantially stable condition
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