Medallion Cut-Off Blades deliver premium, unmatched performance on the job Fiberglass reinforced with a special resinoid bond The ultimate choice for cool, easy, free-cutting of sheet metal, or heavy duty cutting of muffler clamps, bolts and steel rods up to 3/4" thick, as well as spot weld grinding Medallion blade technology can operate at a higher speed than conventional blades, even in excess of 25,000 RPM, Manufacturer: Norton