4.5" Grinding Wheel by Black Hawk Abrasives is a staple in every metal shop. Designed to be attached to a 4-12" angle grinding that accepts 7/8" arbor holes, these discs can rip through metal and last well beyond the industry average. Each 4.5 inch grinding disc is made with A24T aluminum oxide grains which are extra coarse for high stock removal. The discs also come fitted with fiberglass mesh reinforcement for added safety.