About the Carbide Burr: Y UFUTOL-20pcs 3mm(0.118 inch) Shank Solid Tungsten Carbide Double Cut Rotary Files Diamond Burrs Set With 3mm Cutting Head diameter Fits Most Rotary Drill Die Grinder is used for metal Woodworking Drilling Carving Engraving. Safe reliable and convenient to use,Generally use with handheld electric or pneumatic tool drive (can also be used in machine tool), Specifications ： Shank diameter 0.118 inch(3mm) Cutting dia: 0.118 inch 3mm Cutter pattern: double cut Material : solid tungsten carbide steel Size and weight：99X65X13mm，total weight: 94 gram Total length 38mm pakaging : a nice transparen plastic caset !!! Warm Tips!!! Always ensure your burr shank is well inserted into your collet and clamped down tightly Wear an eye mask to protect your eyes from filings.