Flexovit High Performance type 27 grinding wheels are the hardest working aluminum oxide wheels
Flexovit® High Performance™ A1236 Grinding Wheel, Type 27 Depressed Center, General Purpose, Outside Diameter: 4-1/2 Inch, Thickness: 1/4 Inch, Arbor Hole / Thread Size: 7/8 Inch A.H., Grit: 30, Abrasive Type: Aluminum Oxide, Max Speed: 13300 Rpm, Mounting: Arbor, Product / Materials Abraded: Metal/Stainless Steel