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 15350 Contact Arm Assembly, 1 Dia. x 2 W, Serrated Wheel, 90 Durometer
Dynabrade 50008 Collet Body, 3/8"-24 Thread, 200 Series, 1 hp Router
Dynabrade 57814 3-2/3" W x 7" L Dynabug Orbital Sander, Central Vacuum, .28 HP, 10,000 RPM, 3/32" Orbit 
