NortonĀ® Norzon Plus 66253048896 Grinding Wheel, Type 27 Depressed Center, Outside Diameter: 9 Inch, Thickness: 1/8 Inch, Arbor Hole / Thread Size: 7/8 Inch A.H., Grit: 24 (Coarse), Abrasive Type: Ceramic Alumina/Zirconia Alumina, Bond Type: Resin, Max Speed: 6600 Rpm, Mounting: Arbor, Product / Materials Abraded: Metal/Stainless Steel