Aluminum Oxide, Connector Size 1 in, Connector Type Unthreaded Hole, Grit 60, 80, Overall Diameter 5 in, Overall Thickness 1 in, Compatible Tool Type Bench Grinder, Pedestal Grinder, Primary Material Application Aluminum, Brass, Bronze, Cast Iron, Copper, Nickel Alloy, Stainless Steel, Steel, Titanium, Tool Steel, Specification Gemini, Wheel Hardness Not Rated, Wheel Type Type 1, Maximum Operating Speed 4,970 RPM, Reducer Bushing Size 1/2 in, 5/8 in, 3/4 in, 7/8 in, Series 57A, Grade Medium