Heat Treatment

Heat treatment is often used to improve the aluminium’s strength and hardness.

Our 5 metre heat treatment facility, stretch and de-twist machine enables Capalex to supply material to the most demanding aerospace specifications.

If at all unsure, our quality department can advise on which temper would be best for your end use, during your initial enquiry.

Common Aluminium Tempers
'T' Heat treated (ie. For age hardening alloys) the ‘T’ will always be followed by one or more digits.
O Annealed.
F As fabricated.
T1 Cooled from an elevated temperature shaping process and naturally aged.
T2 Cooled from an elevated temperature shaping process, cold worked and naturally aged.
T3 Solution heat-treated, cold worked and naturally aged.
T4 Solution treated and naturally aged.
T5 Cooled from an elevated temperature shaping process and artificially aged.
T6 Solution heat-treated then artificially aged.
T7 Solution heat-treated and then artificially aged.
T8 Solution heat-treated, cold worked and artificially aged.
T9 Solution heat-treated artificially aged and cold worked.
One or more digits may be added to T1 to T9 to indicate further variations for tempers.
T351 Solution heat-treated, stress relieved by stretching a controlled amount. The aluminium receives no further straightening after stretching. Applies to plate, rolled or cold finished rod and bar, to die or ring forgings and to rolled rings.
T3510 Solution heat-treated by stretching a controlled amount and naturally aged. The aluminium receives no further straightening after stretching. Applies to extruded rod, bar, shapes and tubing and to drawn tubing.
T3511 As T3510 but also refers to products that may receive minor straightening after stretching to comply with standard tolerance.
T352 Applies to products that are stress –relieved by compressing after solution heat treatment or after cooling from a hot – working process to produce a permanent set of 1 to 5 %.
T651 Solution heat-treated, stress relieved by stretching a controlled amount and then artificially aged. The aluminium receives no further straightening after stretching.
T6510 Solution heat-treated, stress relieved by stretching a controlled amount and then artificially aged. The aluminium receives no further straightening after stretching.
T6511 As T6510 except that minor straightening is allowed after stretching to comply with standard tolerances.
T73 Solution heat-treated and then artificially overaged in order to achieve the best stress corrosion resistance.
T732 Solution heat-treated and then artificially overaged in order to achieve the best stress corrosion resistance.
T7651 Solution heat-treated, stress relieved by stretching a controlled amount and then artificially over aged in order to achieve a good exfoliation corrosion resistance. The aluminium receives no further straightening after stretching.
T76510 Solution heat-treated, stress relieved by stretching a controlled amount and then artificially over aged in order to achieve a good exfoliation corrosion resistance.The aluminium receives no further straightening after stretching.
T76511 As T76510 except than minor straightening is allowed after stretching to comply with standard tolerances.
Capital Aluminium Extrusions Limited
Cleator Moor, Cumbria,
CA25 5QB, UNITED KINGDOM.