NortonĀ® GeminiĀ® 66252809618 Cup Stone, Type 11, Diameter: 6 Inch Face, 4-3/4 Inch Back, Length: 2 Inch, Wall Thickness: 1-1/2 Inch Rim, 3/4 Inch Back, Grade: Q, Grit: 16, Abrasive Type: Aluminum Oxide, Bond Type: Resin, Max Speed: 6000 Rpm, Bore / Shank Diameter: 5/8-11, Shape/Form: Cup, Mounting: Threaded, Product / Materials Abraded: Iron And Stainless Steel