DEWALT DW8406 5-Inch by 1/4-Inch by 5/8-Inch-11 Aluminum Grinding Wheel (10-Pack) Aluminum oxide grain combination for long wheel life in aluminum and other soft metals 5/8-inch-11 arbor with A30N specs Ideal for specialty grinding for aluminum and other non-ferrous materials Max RPM 12,200 One Year Warranty, One Year Service, 30 day no risk satisfaction