This topic reminded me.....[:0] Years ago, I bought an old saw mill blade, about 3 feet in diameter. My intention was to cut it into blades and make knives. Well, folks, I learned something about old blade steel. A hacksaw wouldn't touch it. Even one of those round, diamond imbedded blades for hacksaws would hardly scratch the rust. I was told a welding torch would ruin the temper. Somebody directed me to a guy with a CNC high pressure water cutter thingy. He wanted $30.00 per blade to cut out. Needless to say, the blade is still intact waiting for me to sell at a yard sale to a painter or whatever. I would still like to cut up into knife blades but am stymied at this point.