Norton Cup Wheel, Series: 32A, 6 x 4-1/2 in Wheel Diameter, 2 in Wheel Thickness, 1-1/4 in Center Hole, 46 Grit, Coarse Grade, Aluminum Oxide Abrasive, Wheel Type Number: Type 11, 3820 rpm Maximum, Wheel Hardness: J, Vitrified Bond, Applicable Materials: 400 Series Stainless, Hard Carbon Steel, Soft Carbon Steel, Tool Steel, Aluminum, Cast Iron, Ductile Iron and Gray Iron, Gray Wheel, Cup Wheel Shape