6061 Aluminum: Difference between T6 vs. T6511
· Aluminum temper T6 vs. T66 November 5, 2022. Q. What is the exact process to temper extruded 6063 aluminum to T66? To get to the -T6 temper, the aluminum billet is heated to about 990 °F, then quenched in water, then aged at about 350 °F for around 8 hours. I can't find anything on what processes are changed to achieve T66. Darren Hesse