I have run into this problem a couple times. I can't recall the specifics because it was years ago. I remember a fairly long bolt to be tightened to something like 15 ft-lbs. Although I had thoroughly cleaned the threaded hole and despite a new bolt, just threading the bolt in required more than 15-ft-lbs. When I noticed this I tried the old bolt to see if may the new bolt was out of spec. The old bolt also required excessive torque.How do you deal with a situation like that?