Aluminum Oxide Connector Size 1/2 in Connector Type Unthreaded Hole Grit 60 Overall Diameter 4 in Overall Thickness 1/4 in Compatible Tool Type Cylindrical Grinder Surface Grinder Tool and Cutter Grinder Primary Material Applicationn Nickel Alloy Steel Tool Steel Specification 38A60-KVBE Wheel Hardness K Wheel Type Type 1 Maximum Operating Speed 6 210 RPM Series 38A Grade Medium Bond Type Vitrified Color White Item Straight Grinding Wheel Package Quantity 5