Luminum

Aluminum Tempers In Brief



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
T2
Cooled from an elevated temperature shaping process, cold worked and naturally aged to a substantially stable condition
Usually associated with cast products
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
T42
Solution heat treated and naturally aged to a substantially stable condition
T62
Solution heat treated and naturally aged to a substantially stable condition

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