I didn't want to contaminate any other thread with dribble so thought I would post here.
If anyone ever has issues with a bolt and nut coming loose then this is the answer -- pic below.
In the early 80's we were having an issue at work with a certain machine. The 1" bolts on the trunion mount were constantly coming loose and then the saddle would get pounded out. This caused the centering/press rolls to jump around. It was a HUGE job to cut out these trunion saddles. Some smarty pants some where invented this super bolt. It was THE answer. I remember when we got the first one a guy got rammy on those little torque bolts and actually pulled the threads right off a 1" bolt . Moral of the story -- use a torque wrench. In my trade a torque wrench is a 1/2" impact set on maximum but not in this scenario.