Using "junk yard metal" I decided to check the hardness of some Aluminum Angle I found. There are so many calculators on the internet that I did not have to write and de-bug a spread sheet. I plan on checking this calculation with a real hardness tester too and will let you know if there are any problems. 92 BN is 6061-t6..... 60 BN is 6063-t52. I actually think it is 6063 which is what I used for my stress calculations. A normal 500 kg test is held for 30 sec. so I am not sure if this is entirely accurate, I plan to check it against know material too. I was just so excited I had to post.