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 14643, Scotch-Weld Metal Bonder Acrylic Adhesive DP8407NS, Gray, 490 mLDuo-Pak, 7100179480, 6/case
3M 76783, Cubitron II Hookit Cloth Disc 784F, 120+ XF-weight, 5 in x NH, Die 500X, 7100222757
Dynabrade 53244 7" Dia. Type 27 Vertical Depressed Center Wheel Grinder, 3 HP, 7,200 RPM, 5/8"-11 Spindle
Dynabrade X52V 5" (127 mm) Dia. Central-Vacuum Dynorbital Extreme Random Orbital Sander, .3 HP, 12,000 RPM, 3/32" Orbit, Hook-Face
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 08027, Marine Grade Silicone Sealant, White, 304 mL Cartridge, 7000120476, 12/Case
3M 22408, Roloc Disc 361F, P100 YF-weight, TR, 1-1/2 in, Die R150S, 7000045101 
