Thanks - lots of good ideas here. Yes this is deck hardware (large winch) which I'm trying to remove. Everything is stainless but I don't want to heat is due to the collateral damage. The winch is circular and the bolts are fastened into a stainless steel plate via a threaded hole. What is driving me crazy is the head of the bolt is a slotted screw type, not a hex bolt or something I can actually get a wrench on. I've been using a monkey wrench to apply torque to a screw driver; next I was going to have my wife bang on the top of the screw driver while I twisted... The bolts are about 3 inches long and the slot on the the top is at least a haf inch across. The bolts just laugh at the little hand held impact wrench I have.