DEWALT DW8417 7-Inch by 1/4-Inch by 5/8-Inch-11 Stainless Steel Grinding Wheel High performance aluminum oxide grain for long life and high material removal 5/8-inch-11 arbor with A30S specs Ideal for specialty grinding for heavy metals (stainless steel, super alloys) Max RPM 8,700 One Year Warranty, One Year Service, 30 day no risk satisfaction