This assembly allows the 3M Disc Pad Face Plate to be easily changed without removing the disc pad hub, allowing the operator to use a single tool for multiple applications from heavy grinding to finishing a workpiece.
Some face plates have ribbing on the bottom face. Ribbed face plates provide additional force when needed for optimal fracturing of the abrasive mineral. By reducing the area of contact, or pressure per square inch (PSI), ribbed face plates increase the grinding pressure of the abrasive with the same amount of operator effort, and extend disc life when dulling is a problem.
Choose a plate with the level of firmness needed for the application?a lighter density face plate for lighter weight grinding applications, and a harder density face plate for more heavyweight grinding applications. Using the correct face plate for the application ensures that the abrasive mineral will fracture as it should, maximizing the life of the abrasive. The plate comes in one of four different colors that indicate the density so the correct plate can be easily identified in the workroom: red = extra hard (for heavy grinding with the coarsest grades), black = hard (for heavy metal removal, large welds, etc.), gray = medium (for general purpose grinding and finishing), and white = soft (for finishing operations on flat or contoured surfaces).

3M 77197, Scotch-Brite™ Roloc™ Deburr and Finish PRO Unitized Wheel,TR, 3 in x 1/8 in x NH, 8C CRS+, 7100109130, 40/box
Dynabrade 60052 .1 hp Straight-Line Quick-Change Pencil Grinder, Rear Exhaust, 35,000 RPM, 3/32" Collet
3M 16112, PPS Lid & Liner Kit, Midi (13.5 fl oz), 200 Micron Full
Diameter Filter, 50 Lids & Liners per kit, 7100020094
3M 33780, 641WY 1/4" X 24", 400 Mesh Diamond Cloth Belt, 7010534915
3M 11411, Roloc Disc 361F, 50 YF-weight, TR, 1 in, Die R100N, 7000045095
3M 05520, Sanding Block, Rubber, 2-3/4 in x 8 in, 7000028366
Dynabrade 53244 7" Dia. Type 27 Vertical Depressed Center Wheel Grinder, 3 HP, 7,200 RPM, 5/8"-11 Spindle
3M™ 72010, Replacement Filter Kit 523-01-29, 7000056891, 1 EA/Case
3M 71346, 675L, 1" X 120", 125u, Diamond Microfinishing Film Belts, 7010534823
3M 33349, 641WY 1/4" X 24", 220 Mesh Diamond Cloth Belt, 7010534919
3M™ 07010, Supplied Air Respirator Hose W-9435-25/07010(AAD), 25 ft, 3/8 in ID, Industrial Interchange Fittings, High Pressure, 7000005374, 1 EA/Case
3M 01552, Green Corps Stikit Disc 255U, 8 in, 24E, 7010298813, 20 discs per carton
3M Scotchkote Liquid Epoxy Coating Spray System HSS Mix Nozzle, RightAngle, 7000058900
3M™ 94275, Versaflo™ Gold Coated Tinted Over-Visor with UV/IR Protection M-967N, 70071696879, 1 EA/Case
3M 58298, Scotch-Weld PUR Applicator Swivel Connector, 7000046653
3M 45714, Cubitron II Hookit Cloth Disc 947A, 120+ X-weight, 3 in x NH, D/F 3HL, Die 300BE, 7100113113
3M 23897, Cloth Belt 777F, 60 YF-weight, 1 in x 18 in, Fabri-lok, Full-flex, 7010307894, 200 per case
3M 15913, Scotch-Brite Roloc Disc High Strength, TR, 2 in X NH A Medium, 7000000710
3M 22394, Roloc Disc 361F, 50 YF-weight, TR, 3 in, Die R300V, 7000045096
Insize 4209-2, LONG HANDLE TELESCOPING GAGE, 1/2 ~ 3/4", 6928640311543
3M 77559, Cubitron II Hookit Cloth Disc 784F, 77559, 36+ to 120+, 5 in x NH, Die 500X, 7100232738
Dynabrade 51702 .1 hp Straight-Line Pencil Grinder, Rear Exhaust, 60,000 RPM, 3/32" Collet
3M 22405, Roloc Disc 361F, P100 YF-weight, TR, 3 in, Die R300V, 7000045102
3M 22393, Roloc Disc 361F, 36 YF-weight, TR, 3 in, Die R300V, 7000045093 
