Depressed Center Grinding Wheel Abrasive Material Zirconia Alumina Connector Size 5/8 In.-11 Connector Type Threaded Hole Grit 24 Overall Diameter 9 in Overall Thickness 0.25 in Primary Material Applicationn Cast Iron Compatible Tool Type Angle Grinder Series BlueFire ZA Wheel Type Type 28 Maximum Operating Speed 6 600 RPM Grade Extra Coarse