Norton Cut-Off Wheel, Small Diameter, Series: U57A, 4 in Wheel Dia, 1/16 in Wheel Thickness, 3/8 in Center Hole, 36 Grit, Very Coarse Grade, Aluminum Oxide Abrasive, 15280 rpm Maximum, Resin Bond, Applicable Materials: 300 Series Stainless, 400 Series Stainless, Aluminum, Brass, Bronze, Copper, Cast Iron, Ductile Iron, Hard Carbon Steel, Soft Carbon Steel, Gray Iron, Super Alloys, Tool Steel and Titanium, Wheel Type Number: Type 01/41 Straight, Wheel Hardness: T, For Use With: Portable Cut-Off Tool Machines, Yes Reinforced