Aluminum oxide is a very hard mineral that maintains sharp points on the grains much longer than natural abrasives such as emery or garnet. The abrasive grains are adhered to the sandpaper with some space between them, known as open-coat construction, to minimize the buildup of dust on the surface of the paper, which would otherwise load the abrasive points. Loading often results from sanding soft materials and can clog the abrasive, shortening the usable life of the sandpaper sheet.
3M 02116, Paper Sheet 346U, 60 D-weight, 9 in x 11 in, 7000120221
$1.11
Factory Stock, 7-10 Day Leadtime
3M Paper Sheet 346U is constructed of aluminum oxide and comes in a range of grades and sizes to accommodate many different projects. The paper backing is durable for coarse sanding, yet flexible enough to be used on curved surfaces. Its cut-rate and durability make this an excellent choice for blending the joints of connecting pieces in wood- and metal-working.

Dynabrade 14000 Dynafile Abrasive Belt Tool
3M 05530, Stikit Soft Hand Pad, 2-3/4 in x 5-1/2 in x 3/8 in, 7000028351
ACS Diamond Cloth Belt, CX1250 3" X 90" 75U
3M 22407, Roloc Disc 361F, 80 YF-weight, TR, 1-1/2 in, Die R150S, 7000045099
Dynabrade 96101 Dynabrade Air Lube 10W/NR 24 Per Box
3M 22409, Roloc Disc 361F, P120 XF-weight, TR, 1-1/2 in, Die R150S, 7000045103
3M 15913, Scotch-Brite Roloc Disc High Strength, TR, 2 in X NH A Medium, 7000000710
3M 49456, EMI Aluminum Foil Shielding Tape 1170, 2 in x 18 yd, 1170-2"X18YD, 7000132702
3M 11412, Roloc Disc 361F, 36 YF-weight, TR, 1 in, Die R100N, 7000045092
3M 22404, Roloc Disc 361F, 80 YF-weight, TR, 3 in, Die R300V, 7000045100
3M 77558, Cubitron II Hookit Cloth Disc 947A, 77558, 40+ to 120+, 6 in x NH, Die 600Z, 7100232737
3M 69619, Hookit Gold Film Disc 255L, P180, 3 in x NH, 7010308369, 50 discs per box
ACS 1/2 in x 18 in Diamond Metal Bond Belt, 120M/125u
3M 45714, Cubitron II Hookit Cloth Disc 947A, 120+ X-weight, 3 in x NH, D/F 3HL, Die 300BE, 7100113113
Standard Abrasives 32953, PSA A/O Disc, 711880, 2 in x NH, 60, 7010310798 
