【Good Material】: These cutters 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, hollow, etc. The processing efficiency is ten times higher than the manual file tool, and almost ten times higher than the small grinding wheel with the handle. 【Widely Fit】: The 3mm round shank is suitable for many electric or air powered tools. There are total 10 pieces of cutters in different shapes that you can use for multiple purposes. 【Portable】: The rotary cutters come in a portable case, no need to organize them. The rotary cutter set can be used for engraving and milling soft wood, plastic and other soft materials, after carving, the surface is smooth. round nose, cylinder with cut end shape, cylinder with spherical nose shape, spherical shape. suitable for most DIY work, such as detail work, cutting, engraving, etching, retouching and finishing. Note: The data are all manual measurement, please please allow 1-3cm error; due to the light and display difference, there would be some color difference, please refer to the actual object received.