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 78128 3" Dia. Coarse NWN VT DynaBrite Locking-Type Disc, 25/pack
Insize 0010-A35, SOUND LEVEL METER, 35dB~130dB, 6974029777004
3M 11412, Roloc Disc 361F, 36 YF-weight, TR, 1 in, Die R100N, 7000045092
Dynabrade 51301 .5 hp Straight-Line Die Grinder
Norton 66261126299 - 2" X 50 Yard 80 Grit Metalite™ Aluminum Oxide Cloth Roll, 1 Each 
