[Hole Saw] is designed to be installed on a mortise chisel to drill holes in wood. The length of the drill bit is 17.5cm/6.88inch, which can effectively reduce the intensity of labor and labor costs * Drills withsquare holes for woodworking cannot be used on electric drills, and square holes must be suitable for square hole drills (tenon and tenon machines). [High Performance] The drill is sharp enough to drill new holes easily, remove cutting materials quickly, and does not produce chips or broken chips, saving energy, time and effort.efforts. At the same time, the chip flute design of the square hole drill can quickly remove wood chips and improve drilling efficiency. [Exquisite Workmanship] High-efficiency square hole design, uniform force, smooth punching without burrs, and low noise processing that is not easy to break. Superb sharpening technology makes the blade sharper and more durable. It's aessential for the family carpentry of carpenters. [Superior Material] The mortise drill bit is made of high quality high speed steel, which has high hardness, wear resistance, high temperature resistance, longer service life, long-term recycling and a positioningprecise. [Wide Application] It is very suitable for all kinds of carpentry, carpentry and wood crafts, construction and maintenance work. *Reminder: The drill seat blades are on one plane, which can guaranteeeffectively the resistance of the drill seat and prevent the bursting of the drill seat during its first use.