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 Cast Iron Steel Compatible Tool Type Angle Grinder Series A24T Wheel Type Type 27 Maximum Operating Speed 13 300 RPM Grade Extra Coarse