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.

Insize 1179-600, DIGITAL RTJ RING GROOVE CALIPER, inside diameter of RTJ ring groove .4-24"/10-600mm, outside diameter of RTJ ring groove 1-24"/25-600mm, 6928640302572
3M 53914, Performance Plus Duct Tape 8979N Nuclear Red, 48 mm x 54.8 m 12.1 mil, 7000049014, 24/ case
3M 05027, Utility Cloth Roll 211K, 150 J-weight, 1-1/2 in x 50 yd, Full-flex, 7100031693 
