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 51812 .1 hp Straight-Line Pencil Grinder, Rear Exhaust, 1000,000 RPM, 3/32" Collet
3M 19764, Utility Cloth Sheet 314D, 9 in x 11 in P320 J-weight, 7000000352
Dynabrade 50321 4-1/2" Dia. Pistol Grip Disc Sander, Rear Exhaust, .7 HP, 11,000 RPM, 5/8"-11 Thread
Insize 0213-A500, INFRARED THERMOMETER, -58?F~716?F/-50?C~380?C, 6940561934700
Standard Abrasives 714179, Aluminum Oxide Handy Roll, P240 J-weight, 1-1/2 in x 50 yd, 7100050575 
