Good Material: These burrs are made of tungsten carbide steel for high hardness and abrasion resistance. Processing hardness up to HRA 85. Function: The cutter set can cut cast iron, cast steel, carbon steel, alloy steel, stainless steel, copper, aluminum, marble, jade, bone, etc. Usage: Widely used for carving, shaping, and removing sharp edges, burrs, and excess material. Compatible with most rotary tools, this drill bit set can be used for engraving, chamfering, grooving, reaming, hollowing, etc. The processing efficiency is ten times higher than the manual file tool, and nearly ten times higher than the small grinding wheel with handle. ?Widely Suitable?: The 3mm round shank is suitable for many tools equipped with an electric or pneumatic motor. There are a total of 10 pieces of burrs in different shapes that you can use for multiple purposes. ?Portable?: The rotary burrs come in a portable case, no need to organize them. The rotary burr set can be used for engraving and milling