Flap discs are made from multiple overlapping pieces of abrasives or 'flaps,’ which is how they got their name. Flap discs were originally designed for right angle grinder applications ranging from heavy stock removal to surface blending and smooth finishing. Flap discs are versatile: they can grind, blend and finish. They are also lightweight, easy to maneuver, and require less change over time. When performing a job, many operators prefer flap discs over grinding wheels due to lower vibration and noise levels. Plus, they offer cooler cutting with minimal scratching.
For instance, grinding wheels must be discarded even after a small area of abrasive is worn out. Comparatively, flap discs remain useful even after the flaps erode, which results in a longer operating life. Compared to a flap disc, grinding wheels are cheaper on a unit cost basis. However, if you consider the versatility, durability and ease of use provided by flap discs, they are more cost-effective in the long run.