Wrought Aluminium and Aluminium Alloys Designation and Temper Designation

Until 1970, designation of wrought aluminium alloys were a mess. The International Alloy Designation System

(IADS) introduced each wrought alloy a 4-digit number that was widely accepted by many countries, it works as

follows: the first digit indicates the major alloying element or elements, as shown in the table:

Major Alloying Elements Series

Pure Aluminium（not less 99.00%） 1×××

Copper 2×××

Manganese 3×××

Silicon 4×××

Magnesium 5×××

Magnesium, Silicon and Mg2Si as strengthening 6×××

Zinc 7×××

Other (including Lithium) 8×××

Standby 9×××

The basic temper designations for aluminium and aluminium alloys are symbolized by a capital letter in English,

and divided into five as following:

Code designation Instructions & Application

F Fabricated No mechanical properties specified. Apply to products that have no

special requirements for work hardening and heat treatment

O Annealed Apply to obtain lowest strength temper by full annealing, O may be

followed by a digit to indicate an annealed condition with special

characteristics.

H Work-hardening or Strain-

hardening

Apply to products with or without additional thermal treatment to

reduce strength. H always is followed by two or more digits.

W Solution heat-treatment W is an unstable temper due to natural aging at room temperature after

solution heat-treatment

T Thermal treatment

Other than F, O ,or H

To produce stable tempers with or without additional strain-hardening,

T is always followed by one or more digits

The minimum tensile strength between H×8 temper and O temper

O temper MPa The D-Value between H×8 temper and O temper, MPa

≤40

45~60

65~80

85~100

105~120

125~160

165~200

205~240

245~280

285~320

≥325

55

65

75

85

90

95

100

105

110

115

120

Temper Instructions & Application

T0 After Solution heat-treatment，naturally aged and cold worked.

Suitable for products after cold worked to improve strength

T1 Cooled from an elevated temperature shaping process and naturally aged.

Suitable for products after shaping process, no longer cold worked ( can be straightened , flattened,

but does not affect the mechanical properties)

T2 Cooled from an elevated temperature shaping process, cold worked, and naturally aged.

Suitable for products after cooled from an elevated temperature, cold worked or straightened,

flattened to improve the strength.

T3 Solution heat treated, cold worked, and naturally aged.

Suitable for products after Solution heat treated, cold worked or straightened, flattened to improve

the strength.

T4 Solution heat treated and naturally aged.

Suitable for products after Solution heat treated, no longer cold worked ( can be straightened ,

flattened, but does not affect the mechanical properties)

T5 Cooled from an elevated temperature shaping process and artificially aged.

Suitable for products after shaping process, no longer cold worked but artificially aged ( can be

straightened , flattened, but does not affect the mechanical properties)

T6 Solution heat treatment and artificially aged.

Suitable for products after solution heat treatment, no longer cold worked ( can be straightened ,

flattened, but does not affect the mechanical properties)

T7 Solution heat treatment and artificially overaged。Suitable for products after solution heat treatment, to obtain some important features, strength on

aged curve over the peak point in the artificially aged.

T8 Solution heat treated, cold worked, and artificially aged.

Suitable for products after cold worked, straightened, flattened to improve the strength.

T9 Solution heat treated, artificially aged, and cold worked.

Suitable for products after cold worked to improve the strength.

T10 Cooled from an elevated temperature shaping process, cold worked, and artificially aged.

Suitable for products after cold worked, straightened, flattened to improve the strength.