6063 aluminium alloy

AA 6063 is an aluminium alloy, with magnesium and silicon as the alloying elements. The standard controlling its composition is maintained by The Aluminum Association. It has generally good mechanical properties and is heat treatable and weldable. It is similar to the British aluminium alloy HE9.

6063 is the most common alloy used for aluminium extrusion. It allows complex shapes to be formed with very smooth surfaces fit for anodizing and so is popular for visible architectural applications such as window frames, door frames, roofs, and sign frames. Applications requiring higher strength typically use 6061 or 6082 instead.

Chemical composition
The alloy composition of 6063 is:

Mechanical properties
The mechanical properties of 6063 depend greatly on the temper, or heat treatment, of the material.

6063-O
Un-heat-treated 6063 has maximum tensile strength no more than 19000 psi, and no specified maximum yield strength. The material has elongation (stretch before ultimate failure) of 18%.

6063-T1
T1 temper 6063 has an ultimate tensile strength of at least 17000 psi in thicknesses up to 0.5 in, and 16000 psi from 0.5 to 1 in thick, and yield strength of at least 9000 psi in thickness up to 0.5 in and 8000 psi from 0.5 in thick. It has elongation of 12%.

6063-T5
T5 temper 6063 has an ultimate tensile strength of at least 20000 psi in thicknesses up to 0.5 in, and 19000 psi from 0.5 in thick, and yield strength of at least 14000 psi up to 0.5 in and 13000 psi from0.5 to 1 in. It has elongation of 8%.

6063-T6
T6 temper 6063 has an ultimate tensile strength of at least 28000 psi and yield strength of at least 23000 psi. In thicknesses of 0.124 in or less, it has elongation of 8% or more; in thicker sections, it has elongation of 10%.

Other tempers
6063 is also produced in tempers T52, T53, T54, T55, and T832, with various improved desired properties.

Uses
6063 is used for architectural fabrication, window and door frames, pipe and tubing, and aluminium furniture.

Welding
6063 is highly weldable, using tungsten inert gas welding. Typically, after welding, the properties near the weld are those of 6063-0, a loss of strength of up to 30%. The material can be re-heat-treated to restore a higher temper for the whole piece.