High-quality materials: High-carbon steel (65#) creates smooth, straight holes quickly and cleanly in hardwood or softwood. 6 sizes: The augers are available in 6 different diameters, including 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, and total length: 230mm/9.05'' to meet your different needs. There is also a separate wooden box for you to keep. Hex shank design: The unique design prevents the hex shank from slipping during operation, and the hex shank can be used with hand drills and drill presses. Self-guiding threading head: The automatic threading head at the front of the drill bit allows the drill bit to be positioned accurately and quickly on the wood for easy drilling. Wide-edge center twist drill. The solid center design makes the drill stable and solid while drilling. The wide inserts allow for faster drilling, easier cutting, and smoother hole walls. DIY Accessories: The auger bits made of high-quality carbon steel are rust-resistant and durable.Good quality product