Rex-Cut Sigma Green 730003 Grinding Wheel, Type 27 Depressed Center, Outside Diameter: 7 Inch, Arbor Hole / Thread Size: 7/8 Inch A.H., Grit: 36 (Coarse), Abrasive Type: Aluminum Oxide, Max Speed: 13300 Rpm, Mounting: Arbor, Product / Materials Abraded: Stainless Steel/Mild Steel/Hard Face/Titanium/Alloys/Aluminum