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Flap disc metal backing consists of abrasive flaps that are attached to a metal backing that helps it to grind and finish surfaces with ease. These discs are commonly used for grinding, blending, finishing, and deburring surfaces on materials such as metal, wood, plastic, and more.
link:https://www.renwa-abrasive.com/coated-abrasives/flap-disc-metal-backing.html
Flap Disc Metal Backing