3mm (1/8") diameter Mandrels will fit most rotary tools; Stem: 1/8 inch (3 mm), length: 8/5 inch (40 mm) Professional Tool: There are 20 different shapes and sizes of rotary cutters, you can choose different types of cutter heads according to job needsQuality Material: The countersink bits is made of quality high speed steel with long life, has the advantages of high hardness, ideal for woodworking and engraving; Works on metal, stone, wood, plastic, foam or resin Suitable for engraving, beveling, chamfering, slotting, reaming, hollowing. Used with a rotary tool to perform carving and engraving work for jeweler, hobbyist, craft makers, model makers, etc. 20 Pcs HSS Rotary Burrs with 1/8" (3mm) Shank Suitable for Dremel for Craft Projects and Creations DIYFeaturesMaterial: Speed Steel Size: The diameter of the handle is 3mm and the total length is 40mmColor: Silver Quantity: 20PCSIdeal for woodworking and engraving; Works on metal, stone, wood, plastic, foam or resinProduct Instructions: This product is mainly used for soft wood carving and milling. The effect of hardwood processing is relatively weak, such as walnut, bodhi root, etc. Do not use as much as possible.Package Contents20PCS X Dremel Wood Cutter Note: The data is all measured manually, please allow 1-3cm error, due to the light and display difference , there will be a certain color difference, the actual object received shall prevail.