Forney 71819 Grinding Wheel with 5/8-Inch-11 Threaded Arbor, Metal Type 27, A24R-BF, 4-1/2-Inch-by-1/4-Inch Aluminum oxide metal grinding wheel Designed for metal grinding, metal abrasion, body work, metal fabrication and general repair work Used on ferrous materials For use on right angle grinders only 5/8-11 threaded arbor for quick change