Designed for portable high speed gas or electric saws. Made of double-reinforced resinoid-bonded aluminum oxide. Cuts structural steel, pipe, rebar, angle iron, and ferrous metals. 1/8" thick. No. 9512: 12", 1" arbor, maximum speed 6300 RPM No. 9416: 12", 20mm arbor, maximum speed 6300 RPM No. 9516: 14", 1" arbor, maximum speed 5400 RPM No. 9418: 14", 20mm arbor, maximum speed 5400 RPM