The Grainger Cut-Off Wheel, GDM 2020R015PF15D-PR1535, is a 10 pack of 4-1/2" x .045" x 5/8"-11 depressed center cut-off wheels made of aluminum oxide abrasive that are designed for cutting, grinding, and deburring metal. They feature a Type 1 depressed center wheel with a reinforced fiberglass mesh construction and resinoid bond. The maximum operating speed is 12,250 RPM with a speed rating of 6660 SFPM. The wheels have a 15/32" arbor hole and 5/8"-11 thread.