K-T Industries 5-6645 4-1/2' 100 Grit Sanding Disc - -. K-T Industries 5-6645 4-1/2" 100 Grit Sanding Disc - -. Used for grinding, finishing, and blend welding . 16,000 Max RPM . 4-1/2-Inch x 100 Grit . Resin fiber discs are made of aluminum oxide grain with a heavy duty fiber backing. They are excellent for purposes of grinding, finishing, and blend welding. Disc size 4-1/2" Grit 100 Maximum RPM 16,000. At we strive to make things simple and easy for our customers. We are dedicated to delivering high quality products at competitive costs. We strive for mutual sales growth and two-way communication with our customers. Service always comes first. Lifetime Warranty - Tools: Socket sets, sockets and accessories, adjustable wrenches and combination wrenches. 90 Day Warranty - Tools: Hex bit sockets, screwdrivers and screwdriver tips, impact drivers, pliers, torque wrenches, hammers, threading and cutting tools, crimping tools, pipe wrenches, gear pullers, porta pullers and clip holders. will repair or replace, without charge, any K-T tool which may fail to function properly within the warranty period by reason of defective workmanship or material. This warranty does not apply to defects due, directly or indirectly, to misuse, abuse, negligence or accidents, repairs or alterations outside our facilities or a lack of maintenance. . . .