Depressed Center Wheels, Abrasive Wheel Type Type 28, Abrasive Wheel Diameter 7 In., Thickness 1/4 In., Arbor Hole Size 5/8 In.-11, Abrasive Material Zirconia Alumina, Abrasive Grit 24, Max. RPM 8600, Series BlueFire, Grade Extra Coarse, Application Ferrous Metal, Gray Iron, Stainless