Depressed Center Grinding Wheel Abrasive Material Aluminum Oxide Connector Size 5/8 In.-11 Connector Type Threaded Hole Grit 24 Overall Diameter 9 in Overall Thickness 0.25 in Primary Material Applicationn Steel Compatible Tool Type Angle Grinder Series A24R Wheel Type Type 27 Maximum Operating Speed 6 600 RPM Grade Extra Coarse