materials-there are four sizes of buried drills (2-5 mm, 5-10 mm, 10-15 mm, and 15-20 mm). These buried drills are made of high -speed steel 4241, which are cut stable and rust -proof, ensuring life and reliability in various applications. Quick and precise drilling-has a 90-degree tip that can achieve precise and efficient cutting to fast punching in materials with a hardness of less than 25 °. It is very suitable for fast and accurate circular pores or cone -shaped holes in metal, wood and even plastic. Easily get clean, clear and accurate results. High-efficiency crumbs-These buried drills to promote fast crumbs, minimize blockage, and make the cutting process faster, cleaner and quieter. Make the cutting process faster, cleaner, and quieter, and improve your overall work efficiency. Compatibility with various machines-In order to obtain the results, use the buried drill bit with desktop rigs, drilling machines, desktop rigs and machining centers. Make sure the backward angle effect. This tool is not recommended for hand drill because it affect the backward angle effect. Multifunctional applications-designed for various materials including wood, metals and plastics, such as plywood, wood, acrylic, PVC plates and metals. These drills are Perfect choices for pores, chamfers, burrs and even non-metal cutting Essence Colour:Silver Material:Metal Package Contents: 1 x countersink drill bit set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.