Depressed Center Grinding Wheel Abrasive Material Aluminum Oxide Connector Size 7/8 in Connector Type Unthreaded Hole Grit 36 Overall Diameter 7 in Overall Thickness 0.125 in Primary Material Applicationn Aluminum Brass Bronze Cast Iron Copper Stainless Steel Steel Compatible Tool Type Angle Grinder Series Challenger II Wheel Type Type 29 Maximum Operating Speed 8 600 RPM Grade Extra Coarse