PFERD 61002 Grinding Wheel, Type 27 Depressed Center, Reinforced, Universal Line PS-FORTE, Outside Diameter: 4-1/2 Inch, Thickness: 1/4 Inch, Arbor Hole / Thread Size: 7/8 Inch A.H., Grade: L (Soft), Grit: 24, Abrasive Type: Aluminum Oxide, Max Speed: 13300 Rpm, Mounting: Arbor, Product / Materials Abraded: Steel/Cast Iron/Stainless Steel (INOX)