The desired length of the strip can be torn from the roll for a specific application. Most grades have a light, J-weight cloth backing that provides the flexibility needed to conform to circular edges, angles, or other contours. Rolls in grades P50 or P60 have a slightly stiffer X-weight backing suitable for more coarse sanding applications. Cloth remains durable even when bent or rolled, without tearing or shelling, but strips can be torn by hand when a smaller piece is needed, without compromising the sanding surface.
Aluminum oxide is a popular choice among industrial professionals because of its fast cut-rate and long life. This mineral makes a tough, durable abrasive that self-fractures to expose fresh cutting edges, whereas traditional natural abrasives dull more quickly. Aluminum oxide is suitable for a wide variety of materials in both woodworking and metalworking, including ferrous alloys. Aluminum oxide abrasive can be used on ferrous and non-ferrous metals, wood, and plastic.

Dynabrade 11486 Dynabelter Accu-Grinder Abrasive Belt Tool, Heavy-Duty
3M 19773, Utility Cloth Sheet 314D, 9 in x 11 in P60 X-weight, 7000000360
3M 19795, Utility Cloth Roll 314D, P400 J-weight, 1-1/2 in x 20 yd, 7100081717
ACS Diamond Grinding Disc, 4-1/2" Dia. X 5/8"-11 Center Hub Thread, Type 29, 36 Grit
3M 19765, Utility Cloth Sheet 314D, 9 in x 11 in P280 J-weight, 7000000353
3M 10455, Cloth Sheet 481W, 220, 9 in x 11 in, 7010294811
Dynabrade 92115 1/2" W x 12" L 220 Grit A/O DynaCut Belt, 50/pack 
