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 11684 Dynabelter Contact Arm Assembly 4" DIA X 5/8" W., 40 Duro Serrated
3M 49689, PSA Cloth Disc 348D, 60 X-weight, 10 in x NH, Die 1000C, 7010326501
Dynabrade 95842 Dynabrade Air Lube 10W/NR, 1 Pint
Dynabrade 40610 Electric Dynafile II Abrasive Belt Tool
3M 05752, Perfect-It Quick Connect Adaptor, 05752, 5/8 in, 7100141852
Dynabrade 15420 Dynafile III Abrasive Belt Tool
3M 05027, Utility Cloth Roll 211K, 150 J-weight, 1-1/2 in x 50 yd, Full-flex, 7100031693 
