WALNUT BITS: Steel tapered drill bits are used to drill holes in wood or other hardwood floors and are suitable for pillar drill bits, impact drill bits, chuck drill bits, etc. It is an essential item for daily woodworking. ROBUST AND DURABLE: Our wood drill bits are made of HSS steel with high hardness, good wear resistance and high heat resistance. The drill bit is ideal for drilling holes in wood, plastic, rubber, PVC and other materials. It is not a power tool and cannot be used for hard objects such as steel, iron and stone. ADJUSTABLE LENGTH: The high-speed steel tapered drill bit set includes an adjustable hexagonal sleeve that can be adjusted by loosening and tightening the screws with a hex wrench. It can also be used to quickly remove accessories. FAST CHIP VENTILATION: The hexagonal tapered countersink drill bit has a chip flute and a three-sided chamfering machine that quickly releases wood chips to get a smooth surface on all types of hardwood. DIFFERENT TYPES OF DRILLS: We have four sizes of wood drill bits with countersink, 6#, 10#, 13#, 16#. Model 6# corresponds to drill size 2.35 mm, model 10# corresponds to 2.5 mm, model 13# corresponds to 2.9 mm, model 16# corresponds to 4 mm and is equipped with a hex wrench of 5.5 * 2 cm. It is enough for your daily needs.