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 33349, 641WY 1/4" X 24", 220 Mesh Diamond Cloth Belt, 7010534919
3M 77558, Cubitron II Hookit Cloth Disc 947A, 77558, 40+ to 120+, 6 in x NH, Die 600Z, 7100232737
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
3M™ 94275, Versaflo™ Gold Coated Tinted Over-Visor with UV/IR Protection M-967N, 70071696879, 1 EA/Case
Air Turbine Tools 310RDM - 1/4" Router Hand Tool Series, 30,000RPM, 33432
3M™ 53797, Flexible Diamond Belt 6451J, 1/2" Dia x 18" L, M125 Micron, Type G, Pattern B2, 7010509272
3M 11000, Roloc Disc 361F, 24 YF-weight, TR, 2 in, Die R200P, 7000028183
3M 66630, Cloth Belt 341D, 50 X-weight, 6 in x 48 in, Film-lok, Single-flex, 7000118864, 20 per case
3M 04029, Scotch-Brite Hand Pad 7447, HP-HP, A/O Very Fine, Maroon, 6 in x 9 in, 7000000728, 60/Case
Dynabrade 55500 .1hp Pencil Grinder, Twin Turbine, 100,000 RPM, Nickel-Plated Aluminum Housing, 1/8" Collet
3M 03601, Plastic Emblem and Trim Adhesive, 1 oz, 7100045880, 24 per case
ACS CX1250 Diamond Belt, 1/2" X 24" 250u
3M 01326, PSA Cloth Disc 348D, P240 X-weight, 3 in x NH, Die 300V, 7000045069 
