DRILL SLEEVE DESIGN - The strength of the drill guide edge is in one plane, effective protection to avoid the cracking situation at the beginning of use. And can clean holes quickly and cleanly in hard or soft wood. U-SHAPED DESIGN - This drill bit features long U-shaped chip drainage grooves, making it easier to discharge wood chips. wood, high efficiency and reliability. WIDE APPLICATION - Square hole drill bit is suitable for density board, medium fiberboard, particle board, wood and other products in wood, perfect for square hole drills and square tenons. HIGH STABILITY - The wood drill bit has a universal handle shape, circular designs at the end of the drill, in order to make the more stable clamping. It can help you finish your work quickly. BEARING STEEL MATERIAL - The drill bit is forged from high quality bearing steel, with high hardness and long service life after overall heat treatment .