Excellent Quality: This square drill bit is made of high-speed steel, with a high-hardness drill bit and a square chisel with sharp edges for continuous cutting and long service life. High-Quality Design: Square drill bits are designed to effectively prevent chipping on first use. No displacement. The saw blade is automatically ejected from both sides of the top of the hole, preventing clogging. High Efficiency: Standard chip ejection design makes it easy to remove wood chips from the edge, improving drilling efficiency. This reduces the labor intensity of construction workers, speeds up construction, and lowers construction costs for the construction, installation, and decoration industries. Various Sizes: Different shank diameters correspond to different sizes of square drill bits, allowing you to drill square holes as needed and easily create precise holes. [Scope of Application] This set of mortise chisel bits is suitable for use with almost all mortising machines and drilling attachments in woodworking. This drill bit is not suitable for electric drills or bench drills.