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™ 17379, Versaflo™ Length Adjusting Breathing Tube BT-30, 7100009685, 1 EA/Case
Dynabrade 13016 Arbor Assembly 1/2"-20 Female Thread - 1/2" Male Thread
Dynabrade 64404 36" W x 60" L (914 mm W x 1,524 mm L) Metal Capture Downdraft Table, 230 V (AC), Side Exhaust
3M™ 72787, Calibration Kit 529-04-48, Large, 7000052154, 1 EA/Case
3M 20905, PSA Cloth Disc 348D, P180 X-weight, 2 in x NH, Die 200P, 7000118876
Dynabrade 98085 1/2"-13 Female _ 5/8"-11 Male, 2-1/2" Length
3M 71358, 641WY 1/4" X 24", 600 Mesh Diamond Cloth Belt, 7010534894
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 01328, PSA Cloth Disc 348D, P180 X-weight, 3 in x NH, Die 300V, 7000045068
3M 05206, Marine Adhesive Sealant 5200, White, 1 oz Tube, 7010325697, 12/Case
3M 20912, PSA Cloth Disc 348D, 40 X-weight, 2 in x NH, Die 200P, 7000118920
Norton 66261013403 - 3" X 1/2" Extra Coarse Grade Silicon Carbide Bear-Tex Rapid Strip TR Stripping Disc, 10 Each
3M 25783, Scotch-Weld PUR Applicator Housing/Shroud Assembly Kit, 7000028623
3M 26120, PPS Series 2.0 Adapter, Type S28, 17.5 mm Female, 19 TPI
Thread, 7100135956
3M 77558, Cubitron II Hookit Cloth Disc 947A, 77558, 40+ to 120+, 6 in x NH, Die 600Z, 7100232737 
