... and most alloys.They off 1,Zirconia flap disc,with fiberglass backing padSize Arbor Grit Maxrpm Type ... # 120# 8600 T27 T292, Aluminum Oxide flap disc,with fiberglass backing padSize Arbor Grit Maxrpm Type4” 5 ... like a depressed center grinding disc and finishing like a fiber disc.Blending and finishing all in ... ,castings and other metal fabrication application.Ideal disc for use on most metals and for ...