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 02119, Paper Sheet 346U, 36 D-weight, 9 in x 11 in, 7000118247
$2.06
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.

Standard Abrasives 713159, Aluminum Oxide Handy Roll, P120 J-weight, 1-1/2 in x 50 yd, 7010290409
Dynabrade 11475 Dynabelter Abrasive Belt Tool, Standard Duty
Dynabrade 11476 Dynabelter Abrasive Belt Tool, Heavy-Duty
3M 34556, Cubitron II Net Sheet Roll, 320+, 80 mm x 10 m, 7100283765, 6 Rolls/Case
3M 26583, Accuspray Refill Pack for PPS Series 2.0, Green, 1.3 mm, 7100152953
Dynabrade 95842 Dynabrade Air Lube 10W/NR, 1 Pint
3M 19773, Utility Cloth Sheet 314D, 9 in x 11 in P60 X-weight, 7000000360
3M 87449 Silver Depressed Center Grinding Wheel, T27 Quick Change, 9 in x 1/4 in x 5/8-11 Center Hub Thread, 7010409732, 20 per case
Standard Abrasives 863198, Quick Change TR A/O Unitized Wheel, 631, 3 in x 1/4 in, 7010330152
Standard Abrasives 713296, Aluminum Oxide Handy Roll, P320 J-weight, 2 in x 50 yd, 7100034517
Standard Abrasives 713297, Aluminum Oxide Handy Roll, P120 J-weight, 2 in x 50 yd, 7100031623
3M 19772, Utility Cloth Sheet 314D, 9 in x 11 in P80 J-weight, 7000000359
3M 19769, Utility Cloth Sheet 314D, 9 in x 11 in P150 J-weight, 7000000357
3M 33446, Cubitron II File Belt, 80+, 1/2 in x 18 in (12.7 mm x 457.2 mm), 7100033186, 10 belts per carton, 5 cartons per case
Standard Abrasives 707195, Aluminum Oxide Handy Roll, P80 J-weight, 2 in x 50 yd, 7100031626 
