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).

ACS CX1250 Diamond Belt, 1/2" X 24" 125u
Standard Abrasives 727334, Buff and Blend Cross Buff HS, A/O Coarse, 1 in x 3/8 in x 2 Ply x 8-32, 7000047211
3M 14270, Disc Pad Face Plate, 4-1/2 in Hard Black, 7000144144
3M 29611, 641WY 1/4" X 24", 100 Mesh Diamond Cloth Belt, 7010534832
3M 62606, Scotch-Weld Threadlocker TL42, Blue, 50 mL Bottle, 7100039193, 10/case
3M 11411, Roloc Disc 361F, 50 YF-weight, TR, 1 in, Die R100N, 7000045095
Dynabrade 13509 Dynastraight Finishing Tool, Rear Exhaust, 6,000 RPM, 5/8" (16 mm) or 1" (25 mm) Dia. Arbor
3M 77559, Cubitron II Hookit Cloth Disc 784F, 77559, 36+ to 120+, 5 in x NH, Die 500X, 7100232738 
