Calling all makers, welders, and DIY enthusiasts! This YUFUTOL set has 20 different solid tungsten carbide rotary burrs (also called rotary files) that'll become your go-to tools for shaping, carving, and grinding. The shank on each one is 3mm (0.118 inches), so they fit perfectly into most small rotary tools like Dremel, as well as pneumatic die grinders. The cutting heads are also 3mm in diameter, and they have a double-cut pattern for efficient material removal. Made from heat-treated solid carbide, these things are tough – they stay sharp and last a long time even when working on hard materials like metal, wood, fiberglass, or ceramic. You can use them for all sorts of tasks: deburring metal edges, porting cylinder heads, wood carving, jewelry making, sculpting, and cleaning up welds. They come in a handy plastic case to keep them organized and safe. Remember to always wear safety glasses, make sure the burr is tightly secured in your tool, and use light pressure – let the tool do the work. Keep them away from kids. A fantastic, versatile set for your workshop!