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.

3M 86992, Diamond Disc, 3" Roloc, 674W, 120 Mesh, TR, 7100143477, Box of 5
Dynabrade 95843 Dynabrade Air Lube 10W/NR, 1 Gallon
3M 15938 Scotch-Brite Surface Conditioning Low Stretch Belt, SC-BL, A/O Medium, 1-1/2 in x 60 in, 7010300824
3M 19764, Utility Cloth Sheet 314D, 9 in x 11 in P320 J-weight, 7000000352
Dynabrade 95848 Dynabrade Gear Oil
3M 19770, Utility Cloth Sheet 314D, 9 in x 11 in P120 J-weight, 7000000358
3M 45714, Cubitron II Hookit Cloth Disc 947A, 120+ X-weight, 3 in x NH, D/F 3HL, Die 300BE, 7100113113
Dynabrade 10690 Filter/Regulator/Lubricator, FRL40, 1/2" NPTAssy. 
