Metal type 27, depressed center, 4-1/2" x .045 x 7/8" arbor, a60t-bf. aluminum oxide metal cutting wheel. designed for metal cutting, metal abrasion, body work, metal fabrication and general repair work. used on ferrous materials. designed to be used on right angle grinders with proper adapters. iso 9001 certified. wheel size: 4-1/2" thickness: .045" arbor: 7/8" spec: a60t-bf max rpm: 13,580 tool type: right angle grinder