This assembly allows 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 foot (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 09413, Scotch-Brite Contour Surface Paint and Varnish Remover 9413NA, 7000052005
3M 16578, Accuspray ONE Spray Gun Kit, 7100096182
3M 64933, Scotch-Brite Pro Hand Pad, PO-HP, 1 - 6 in x 9 in pad 7447 PRO and 1 - 6 in x 9 in pad 7448 PRO, Multi-pack, 7100033494
3M 17181, Scotch-Brite Roloc Unitized Wheel Pack 987S, 2 in, 7000144150
3M 29611, 641WY 1/4" X 24", 100 Mesh Diamond Cloth Belt, 7010534832
3M 21543, Scotch-Brite Roloc Clean and Strip XT Pro Extra Cut Disc, TR, 2 in x NH, A XCS, 7100179815, 60/box
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 33780, 641WY 1/4" X 24", 400 Mesh Diamond Cloth Belt, 7010534915
Dynabrade 95843 Dynabrade Air Lube 10W/NR, 1 Gallon
3M™ 72122, Portable Compressed Air Filter and Regulator Panel 256-02-01, 100 cfm, 8 outlets, with Carbon Monoxide Monitor, 7000052147, 1 EA/Case
3M 22409, Roloc Disc 361F, P120 XF-weight, TR, 1-1/2 in, Die R150S, 7000045103 
