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 19773, Utility Cloth Sheet 314D, 9 in x 11 in P60 X-weight, 7000000360
3M Super Abrasives Roloc Disc, 2" Type-R, Medium AO High Strength, Box of 50
Norton 66254432925 Wheel, 3" X 1/2" X 1/4" Bear-Tex, Rapid Blend, Non-Woven 5 Density, A/O, M Grit, 20 Each
3M 64469 Scotch-Brite Durable Flex Belt, DF-BL, A/O Fine, 3/4 in x 18 in, 7100105418
Standard Abrasives 707195, Aluminum Oxide Handy Roll, P80 J-weight, 2 in x 50 yd, 7100031626 
