A flap disc is a type of abrasive tool used for grinding, polishing, and finishing various materials such as metal, wood, and plastic. It consists of multiple overlapping flaps made of abrasive cloth or paper, which are attached to a central hub. The flaps on a flap disc are angled in a way that allows for a consistent and even grinding or polishing action. This design also helps to reduce heat buildup and prevent gouging or damaging the workpiece. Flap discs are available in different grit sizes, allowing for various levels of material removal and surface finish. They are commonly used in metal fabrication, welding, automotive repair, and woodworking industries.

Some advantages of using flap discs include:

1. Versatility: Flap discs can be used on a wide range of materials, making them a versatile tool for various applications.

2. Longevity: The abrasive flaps on a flap disc tend to wear down gradually, providing a longer lifespan compared to other abrasive tools.

3. Consistency: The overlapping flaps on a flap disc ensure a consistent grinding or polishing action, resulting in a uniform finish.

4. Time-saving: Flap discs can remove material quickly and efficiently, reducing the time required for grinding or polishing tasks.

5. Ease of use: Flap discs are easy to use and can be attached to most angle grinders or power tools with a spindle.

Overall, flap discs are a popular choice for professionals and DIY enthusiasts alike due to their versatility, durability, and ease of use.