Walter Surface Technologies HP™ Cup Wheel, Spin-On, 4 in Wheel Diameter, Aluminum Oxide/Silicon Carbide Abrasive, Wheel Type Number: Type 11, 9100 rpm Maximum, Resinoid Bond, Applicable Materials: Cast Iron, Concrete, Steel and Stainless Steel, 5/8-11 Center Hole Thread, Brown Wheel, Cup Wheel, Specifications Met: ANSI B7.1, EN 12413