Made for a wide range of grinding, shaping and cutting jobs in home workshops, farms and machine shops. Aluminum oxide is recommended for all types of ferrous metals. Wheel dimensions are diameter x thickness x arbor. Thread Size 11, Max. RPM 8,500, Wheels qty. 1, Arbor Size in. 5/8, Wheel Thickness in. 1/4, Wheel Diameter in. 7, Wheel Type Metal grinding wheel.