Depressed Center Grinding Wheel Abrasive Material Aluminum Oxide Connector Size 7/8 in Connector Type Unthreaded Hole Grit 24 Overall Diameter 9 in Overall Thickness 0.25 in Primary Material Applicationn Steel Compatible Tool Type Angle Grinder Series XA24Q Wheel Type Type 27 Maximum Operating Speed 6 600 RPM Grade Extra Coarse