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 22405, Roloc Disc 361F, P100 YF-weight, TR, 3 in, Die R300V, 7000045102
3M 77558, Cubitron II Hookit Cloth Disc 947A, 77558, 40+ to 120+, 6 in x NH, Die 600Z, 7100232737
3M 11414, Roloc Disc 361F, P120 XF-weight, TR, 1 in, Die R100N, 7000045104
Standard Abrasives 712149, Aluminum Oxide Handy Roll, P100 J-weight, 1-1/2 in x 50 yd, 7010295370
3M 01326, PSA Cloth Disc 348D, P240 X-weight, 3 in x NH, Die 300V, 7000045069
Norton 66261126299 - 2" X 50 Yard 80 Grit Metalite™ Aluminum Oxide Cloth Roll, 1 Each 
