This subject has always had me curious so I thought I'd ask you guys. When you use torque-to-yield head bolts, or the type that stretch when tightened, I understand the concept of the bolt reaching the yield point and relaxing a bit, but does the bolt "reharden" itself after stretching? In otherwords, what's going on at the molecular level? I don't know very much about how metal/steel can be heat treated, tempered, annealed, etc., but I am familiar with some welding and understand how steel can be heated and distorted and after normalizing still have the same strength or properties as before.
Any insight?
Dan
Any insight?
Dan