Extra-large Premier Red FatBoy is made with self-sharpening zirconia alumina abrasive on cloth backing. Resin bond holds abrasive in place, allowing each grain to fracture and continually produce sharp edges during operation. Aggressive material removal rate stays constant from first to final cut. For weld bead grinding and fine carbon and stainless steel polishing, flap disc is 4 1/2 and 7 in. dia.