Recessed Grinding Wheel, Abrasive Material Aluminum Oxide, Connector Size 1 1/4 in, Connector Type Unthreaded Hole, Grit 60, Overall Diameter 7 in, Overall Thickness 3/4 in, Wheel Hardness I, Specification 38A60-IVBE, Wheel Type Type 5, Compatible Tool Type Cylindrical Grinder, Surface Grinder, Primary Material Applicationn Nickel Alloy, Steel, Tool Steel, Maximum Operating Speed 3,600 RPM, Recess Depth 1/4 in, Recess Diameter 2 3/4 in, Bond Type Vitrified, Color White, Grade Medium