Dish Grinding Wheel Abrasive Material Aluminum Oxide Back Thickness 5/16 in Connector Size 3/4 in Connector Type Unthreaded Hole Grit 60 Overall Diameter 4 in Overall Thickness 1/2 in Rim Thickness 3/16 in Primary Material Applicationn Aluminum Cast Iron Stainless Steel Tool Steel Compatible Tool Type Tool and Cutter Grinder Specification 32A60-KVBE Wheel Hardness K Wheel Type Type 12 Maximum Operating Speed 6 210 RPM Bond Type Vitrified Color Purple Grade Medium Series 32A