Forney 72375 Grinding Cup Wheel, Type 11 Flared Metal with 5/8-Inch-11 Threaded Arbor, A16Q, 5-Inch-by-2-Inch Designed for removal of large amounts of stock 5-Inch by 2-Inch with a 5/8-Inch-11 threaded hub Made from aluminum oxide Max RPM is 7,250