SHDIATOOL 4 Inch Diamond Grinding Wheel for Granite Marble Iron Steel Masonry Cup Disc Fits 7/8 Arbor

1 pc 4 Inch Vacuum Brazed Diamond Grinding Disc - 100mm Diameter, 30/40 Grit, for Iron, Steel, Granite, Marble, Ceramic - Dry/Wet Use, High Speed, Long Life 100mm (4 Inch) Diameter, 22.23mm (7/8 Inch) Bore, Includes Reducer Washer for 16mm (5/8 Inch) Shaft - 30/40 Diamond Grit for Precision Grinding，the recommend speed is 9072RPM Advanced Vacuum Brazed Technology Ensures Faster Grinding Speed and Longer Lifespan Compared to Conventional Discs Versatile Dry & Wet Use - Ideal for Grinding Iron, Steel, Granite, Marble, Natural Stone, Ceramic, and More - Perfect for Professional and DIY Projects Premium Quality Diamond Disc - Reduces Sparks, Ensures Faster, Safer, and Smoother Grinding on Iron and Steel