We gave these discs an open coat construction and a load-resistant coating to help prevent clogging of the disc to optimize cut and prolong disc life. The Hookit (hook-and-loop) attachment system makes disc changes fast and easy, meaning the disc can be used again and again for the extent of the abrasive life.
We chose silicon carbide, which is a very hard and sharp mineral commonly used for low-pressure applications such as paint prep and the final stages of whitewood sanding. While it may have a shorter life than aluminum oxide, it produces a superior finish and should be used where the best possible finish is desired.
Sandpaper discs cut better and last longer when dust isn’t loading the cutting surface of the abrasives. Open coat construction means the abrasive grains are placed with space between them to help evacuate sanding dust and avoid clogging the cutting edge of the grains. The load-resistant coating also allows the disc to continue cutting even when sanding softwoods, paints, and other materials that would, otherwise, clog the disc and hinder sanding ability.
Together with the 3M Hookit backing, these features add up to increased productivity and reduced material consumption.

Dynabrade 51700 .1 hp Straight-Line Pencil Grinder, Rear Exhaust, 60,000 RPM, 1/8" Collet
Insize MLP-CM60-CHUCK, CUTTING BLADE CHUCK, 32mm, 6940561949100
Dynabrade 96101 Dynabrade Air Lube 10W/NR 24 Per Box
Standard Abrasives 880413, Buff and Blend GP Wheel, 3 in x 1 Ply x 1/4 in, A MED, 7100095202
3M 22397, Roloc Disc 361F, 60 YF-weight, TR, 1-1/2 in x NH, 7000045097
3M 22404, Roloc Disc 361F, 80 YF-weight, TR, 3 in, Die R300V, 7000045100
3M 28849, Unitized Wheel Mandrel 28849, 1-7/8 in x 1/4 in x 3/4 in x 1/2 in, 7100082548
3M 77558, Cubitron II Hookit Cloth Disc 947A, 77558, 40+ to 120+, 6 in x NH, Die 600Z, 7100232737 
