CGW Cup Wheel, 6 x 4-3/4 in Wheel Diameter, 2 in Wheel Thickness, 24 Grit, Hard/Coarse Grade, Aluminum Oxide Abrasive, Wheel Type Number: Type 11, 6048 rpm Maximum, Wheel Hardness: Q, Resin Bond, Applicable Materials: Ferrous Metals and Tough Steel, 5/8-11 Center Hole Thread Size, Cup Wheel Shape