Authentic Makita Depressed Center Grinding Wheel Size: 9″ (230mm) x 1/4″ (6mm) x 7/8″ (22.2mm) For Metal A24R-BF Model: D-18487 Can be used for cutting and grinding Ideal to use on metals Abrasive Grade: Coarse Abrasive Material: Brown Fused Aluminum Max RPM: 80m/s (4800m/min) 6,600 RPM