DEWALT DW8410 4-Inch by 1/4-Inch by 5/8-Inch Stainless Steel Grinding Wheel (25-Pack) High performance aluminum oxide grain for long life and high material removal 5/8-inch arbor with A30S specs Ideal for specialty grinding for heavy metals (stainless steel, super alloys) Max RPM 15,200 One Year Warranty, One Year Service, 30 day no risk satisfaction