The basic tempering state of aluminum alloy is represented by a capital letter. The
subdivided tempering state code is represented by the basic tempering state code followed by one or more digits.
F tempering state is a free processing state, which is suitable for aluminum alloys that have no special requirements for work hardening and heat treatment conditions during the forming process. The mechanical properties of this F state aluminum alloy are not specified.
O temper condition is the annealed condition and is suitable for processed aluminum alloys that have been fully annealed to obtain the lowest strength.
H is the tempered state, work hardening state, which is suitable for aluminum alloys that have been hardened to improve their strength. After hardening, aluminum alloys can undergo additional heat treatment to reduce their strength. H must be followed by two or three digits.
T tempering state, heat treatment state, is applicable to aluminum alloys that have reached a stable state after work hardening after heat treatment. T state must be followed by one or more digits.
