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 85364, Aluminum Foil Tape 425, Silver, 2 1/2 in x 60 yd, 4.6 mil, 7010379571
Dynabrade 78591 3/8" Dia. x 1" W x 1/8" Center Hole, 80 Grit, 100/pack
Insize 0130-L110, LIGHT METER (BASIC TYPE), 6974029776564
Norton 66254432925 Wheel, 3" X 1/2" X 1/4" Bear-Tex, Rapid Blend, Non-Woven 5 Density, A/O, M Grit, 20 Each
Norton 66261126299 - 2" X 50 Yard 80 Grit Metalite™ Aluminum Oxide Cloth Roll, 1 Each
3M 19768, Utility Cloth Sheet 314D, 9 in x 11 in P180 J-weight, 7000000356 
