Flap discs are commonly used in metalworking and fabrication industries for deburring, grinding, and finishing applications. They are also used in woodworking and automotive industries, as well as for DIY and home improvement projects. Flap discs are versatile tools that can be used on a variety of surfaces, including metal, wood, plastics, and ceramics.

One of the advantages of using a flap disc is its ability to remove material quickly and efficiently, while also producing a smooth finish. The fan-like shape of the flaps provides a larger surface area, allowing for faster material removal. Flap discs are also durable and long-lasting, making them a cost-effective choice for many applications.

Flap discs come in a range of sizes, from small hand-held tools to larger industrial machines, and are available in different shapes, including flat, conical, and angled. They can also be used with different types of power tools, such as angle grinders, bench grinders, and drills.

Overall, flap discs are a versatile and efficient tool for a variety of grinding, sanding, and finishing applications, and can help to save time and improve the quality of the finished product.

Here is a general size and grit chart for flap discs:

Note that this is just a general guide and specific sizes and grits may vary depending on the intended use of the flap disc. It is important to choose the right size and grit of flap disc for your specific application and to follow proper safety precautions when using the tool.