Firepower 1423-2220 Type 29 Zirconia Flap Disc with Hub, 36 Grit, 4-1/2-Inch x 5/8-Inch Measures 4.5 Inch x 5/8-inch-11 NC Higher durability than conventional fiber discs Designed to wear away evenly and present a constantly fresh working surface Cut and finish at the same time with consistent finish For coarse and intermediate grinding and machining of welds, debarring, rust removal, snagging, removal of paint, etc.