How does the DW4945, or any backing pad, fit on the spindle of the new DEWALT 4 1/2" grinders? Support November 05, 2020 18:54 Updated Follow In order to use a backing pad on this grinder you should remove the inner flange/washer and put the pad onto the spindle. Related articles What is the warranty on my router, planer and joiner? Who can I contact for support with my gas powered pressure washer? Why did I get a hex wrench with my new DEWALT Angle Grinder? Comments 0 comments Please sign in to leave a comment.