T651 versus T6 Aluminum

[Nellysdad]

I am told that T6 and T651 are "basically" the same.
I stress relieve T6 in-house at 320-350 deg for 4 hrs after machining and that has worked fine.
I believe that T651 is already stress relieved via stretching. Can I use the same technique without altering the FINAL properties too much?

 

[metengr]

What is the Aluminum alloy that you are using in the T6/T651 temper designations? Normally T6 temper refers to sheet (less than 0.250") product, and T651 temper refers to plate product.

 

[TVP]

T6 and T651 produce essentially the same properties, but they are not the same. You are correct that T651 is a stress-relieved version of T6. The aging temperature of 6061 is usually 320 F, so I would certainly not exceed that as a stress relieving temperature.