Depressed Center Grinding Wheel Abrasive Material Aluminum Oxide Connector Size 5/8 In.-11 Connector Type Threaded Hole Grit 24 Overall Diameter 4 1/2 in Overall Thickness 0.25 in Primary Material Applicationn Nickel Alloy Stainless Steel Steel Compatible Tool Type Angle Grinder Series A24R Wheel Type Type 27 Maximum Operating Speed 13 300 RPM Grade Extra Coarse