... steel,aluminium,and most alloys.They off 1,Zirconia flap disc,with fiberglass backing padSize Arbor Grit Maxrpm Type 4” ... 40# 60# 80# 120# 8600 T27 T292, Aluminum Oxide flap disc,with fiberglass backing padSize Arbor Grit Maxrpm Type4” 5/8 ... of welds,castings and other metal fabrication application.Ideal disc for use on most metals and for wide ... discs.l Suitable for Angle Grinder. nonabrasive flap disc