【HIGH QUALITY MATERIAL】High carbon (65 ) steel material quickly and cleanly forms smooth, straight holes in hardwood or cork. 【6 SIZES】There are 6 different diameters of auger drill bits, including 10mm, 12mm, 14mm,16mm, 18mm, 20mm total length: 230mm/9.05', to meet your various needs. 【HEXAGONAL SHANK DESIGN】 The unique design allows the hexagonal shank not to slip during operation, and the hexagonal shank can be used with hand drills and drill presses. 【HEAD SELF DIRECTED THREAD 】The automatic threaded head on the front of the bit allows the bit to be positioned precisely and quickly on the wood for easier drilling. Wide blade center twist drill bit. The solid center design makes the drill stable and sturdy during the drilling process. Wide blade allows for faster drilling, easier chipping and smooths hole walls. 【DIY ACCESSORY】High quality carbon steel auger tips are rust resistant and durable .