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 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 65055, Scotch-Brite Heavy Duty Hand Pad 7440, HP-HP, A/O Medium, 6 in x 9 in, 7100080459, 40/Case
3M 15913, Scotch-Brite Roloc Disc High Strength, TR, 2 in X NH A Medium, 7000000710
3M 20922, PSA Cloth Disc 348D, 60 X-weight, 1-1/2 in x NH, Die 150S, 7010326528.
3M 29831, Sanding Screen, 180 Grit, 18 in x NH, 7100160238
Dynabrade 53245 7" Dia. Type 27 Vertical Depressed Center Wheel Grinder, 3 HP, 8,500 RPM, 5/8"-11 Spindle
3M 03647, Scotch-Brite Edger Disc Pad, 7 in x .875 in, 7000133920
3M™ 72013, Adapter 529-04-50, 110-120 VAC, 7000131705, 1 EA/Case
3M™ 53797, Flexible Diamond Belt 6451J, 1/2" Dia x 18" L, M125 Micron, Type G, Pattern B2, 7010509272
3M™ 07012, Supplied Air Hose W-9435-100/07012(AAD), 100 ft, 3/8 in ID, Industrial Interchange Fittings, High Pressure, 7000005375, 1 EA/Case
3M 33780, 641WY 1/4" X 24", 400 Mesh Diamond Cloth Belt, 7010534915
Dynabrade 51301 .5 hp Straight-Line Die Grinder
3M 01326, PSA Cloth Disc 348D, P240 X-weight, 3 in x NH, Die 300V, 7000045069
3M 08994, Scotch-Weld Epoxy Adhesive DP100, Clear, 48.5 mL Duo-Pak, 7100148763, 12/case
3M™ 72016, Remote Alarm & Strobe 529-05-20, Audible, 7000131708, 1 EA/Case
3M 33349, 641WY 1/4" X 24", 220 Mesh Diamond Cloth Belt, 7010534919
3M 05205, Marine Adhesive Sealant 5200, Black, 3 oz Tube, 7000118402, 6/Case
3M 19674, Scotch-Seal Industrial Sealant 800, Reddish Brown, 5 oz Tube, 7000000792, 36/Case
3M 30202, Disposable Plastic Wheel Maskers, 12 in - 15 in, 125 per box, 7000125074
3M 62612, Scotch-Weld Threadlocker TL71, Red, 10 mL Bottle, 7100039197, 10/case
3M™ 17379, Versaflo™ Length Adjusting Breathing Tube BT-30, 7100009685, 1 EA/Case
3M 22408, Roloc Disc 361F, P100 YF-weight, TR, 1-1/2 in, Die R150S, 7000045101 
