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 01328, PSA Cloth Disc 348D, P180 X-weight, 3 in x NH, Die 300V, 7000045068
3M 11412, Roloc Disc 361F, 36 YF-weight, TR, 1 in, Die R100N, 7000045092
3M 26583, Accuspray Refill Pack for PPS Series 2.0, Green, 1.3 mm, 7100152953
Dynabrade 53533 Cone or Plug Grinder (Triple Extension)
3M 05009, Utility Cloth Roll 211K, 100 J-weight, 1 in x 50 yd, Full-flex, 7100016843 
