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 20931, PSA Cloth Disc 348D, P100 X-weight, 1 in x NH, Die 100N, 7000118915
3M 47201, Polyurethane Sealant 540, Black, 600 mL Sausage Pack, 7100198009, 12/Case
Air Turbine Tools 310RDM - 6mm Router Hand Tool Series, 25,000RPM, 33423
Dynabrade 96101 Dynabrade Air Lube 10W/NR 24 Per Box
3M 62607, Scotch-Weld Threadlocker TL42, Blue, 250 mL Bottle, 7100039192, 2/case
Air Turbine Tools 310RSV - 6mm Router Hand Tool Series, 40,000RPM, 33441
3M 36877, Self-Stick Liquid Protection Fabric, Blue, 6 in x 300 ft per Roll, 7100169347, 4 Rolls Per Pack
3M 11419, Roloc Disc 361F, P240 XF-weight, TR, 2 in, Die R200P, 7000045105 
