Depressed Center Grinding Wheel Abrasive Material Zirconia Alumina/Silicon Carbide Connector Size 3/8 in Connector Type Unthreaded Hole Grit 24 Overall Diameter 4 in Overall Thickness 0.25 in Primary Material Applicationn Stainless Steel Steel Compatible Tool Type Angle Grinder Series BlueFire ZC Wheel Type Type 27 Maximum Operating Speed 15 280 RPM Grade Extra Coarse