PFERD 61001 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: 5/8-11 Thread, Grade: L (Soft), Grit: 24, Abrasive Type: Aluminum Oxide, Max Speed: 13300 Rpm, Mounting: Threaded, Product / Materials Abraded: Steel/Cast Iron/Stainless Steel (INOX)