States of Aluminum Alloys

State Symbol	Definition
F	It is the initial manufacturing state, without any other treatment (without special control of temperature or surface hardening). Mechanical property limits are not specified for this state.
O	Soft. Annealed to achieve the lowest tensile strength.
H111	Annealed and slightly strain-hardened – tensile strength is lower than that of the H11 state through further cold working (stretching, stress-relieving).
H112	Slightly strain-hardened through high-temperature working or slight cold working; mechanical property limits are specified.
H12	Quarter-hard. Strain-hardened by rolling to achieve a tensile strength halfway between "O" and H14.
H14	Half-hard. Strain-hardened by rolling to achieve a tensile strength halfway between "O" and H18.
H16	Three-quarters hard. Strain-hardened by rolling to achieve a tensile strength halfway between H14 and H18.
H18	Hard. Strain-hardened by rolling to the highest tensile strength normally achievable.
H19	Extra hard. Strain-hardened by rolling to a tensile strength at least 10 MPa higher than that of H18; generally used for aluminum (1xxx) and soft alloys (3xxx, 5xxx).
H22	Quarter-hard. Strain-hardened and partially annealed by rolling to achieve a tensile strength halfway between "O" and H24.
H24	Half-hard. Strain-hardened and partially annealed by rolling to achieve a tensile strength halfway between "O" and H28.
H26	Three-quarters hard. Strain-hardened and partially annealed by rolling to achieve a tensile strength halfway between H24 and H28.
H28	Hard. Strain-hardened and partially annealed by rolling to the highest tensile strength normally achievable.
H32	Quarter-hard. Strain-hardened and stabilized to achieve a tensile strength halfway between "O" and H34.
H34	Half-hard. Strain-hardened and stabilized to achieve a tensile strength halfway between "O" and H38.
H36	Three-quarters hard. Strain-hardened and stabilized to achieve a tensile strength halfway between H34 and H38.
H38	Hard. Strain-hardened and stabilized to the highest tensile strength normally achievable.
T3	Solution treated, cold worked, and naturally aged to obtain a stable state.
T3510	Solution treated, stress-relieved during controlled stretching (permanent deformation 1-3%), and naturally aged. These products should not undergo any stretching operations after the controlled stretching.
T3511	Similar to T3510, except that these products may undergo minor stretching operations after controlled stretching, within standard tolerances.
T4	Solution treated and naturally aged to obtain a stable state.
T4510	Solution treated, stress-relieved during controlled stretching (permanent deformation 1-3%), and naturally aged. These products should not undergo any stretching operations after the controlled stretching.
T4511	Similar to T4510, except that these products may undergo minor stretching operations after controlled stretching, within standard tolerances.
T5	Cooled after a high-temperature processing procedure and artificially aged.
T6	Solution treated and artificially aged.
T64	Solution treated and artificially aged between T6 and T61 to improve formability.
T6510	Solution treated, stress-relieved during controlled stretching (permanent deformation 1-3%), and artificially aged. These products should not undergo any stretching operations after the controlled stretching.
T6511	Similar to T6510, except that these products may undergo minor stretching operations after controlled stretching, within standard tolerances.
T66	Solution treated and then artificially aged, with mechanical properties more pronounced than T6, produced by a special controlled process.
T7	Solution treated and artificially aged.
T73	Solution treated and artificially aged with a special heat treatment to increase corrosion resistance.
T73510	Solution treated, stress-relieved during controlled stretching (permanent deformation 1-3%), and artificially aged with a special treatment to increase corrosion resistance. These products should not undergo any stretching operations after the controlled stretching.
T73511	Similar to T73510, except that these products may undergo minor stretching operations after controlled stretching, within standard tolerances.
T8	Solution treated, cold worked, and artificially aged.
T8510	Solution treated, stress-relieved during controlled stretching (permanent deformation 1-3%), and artificially aged. These products should not undergo any stretching operations after the controlled stretching.
T8511	Similar to T8510, except that these products may undergo minor stretching operations after controlled stretching, within standard tolerances.

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