Amazon.com: Norton Metal Depressed Center Abrasive Wheel, Type 27, Aluminum Oxide, 5/8"-11 Hub, 4-1/2" Diameter x 1/4" Thickness (Pack of 10) : Industrial & Scientific
Amazon.com: Norton Charger Plus Depressed Center Abrasive Wheel, Type 27, Zirconia Alumina and Aluminum Oxide, 5/8"-11 Hub, 4-1/2" Diameter x 1/8" Thickness (Pack of 1) : Industrial & Scientific