Additions to Cu and Al alloy Designations
Temper designation scheme for alloys: a letter and possibly a one- to three-digit number:
Ø F, H, and O represent, respectively, the as-fabricated, strain hardened, and annealed states.
Ø T3 means that the alloy was solution heat treated, cold worked, and then naturally aged (age hardened).
Ø T6 means that the alloy was solution heat treated followed by artificial aging.