[Hole Saw] Designed to be mounted on a mortise chisel used for drilling holes in wood. The length of the drill bit is 17.5cm/6.88in, which can effectively reduce the intensity labor and labor cost.* The drill square hole drill for woodworking can not be used on electric drill, square hole should be suitable for square hole drill (tenon machine).High PerformanceThe drill bit is sharp, can easily drill new holes, quickly remove cutting materials, no chips or broken chips, saving time and effort. At the same time, the design of the chip flute of the square hole drill can quickly remove wood chips and improve drilling efficiency.Exquisite workmanshipEfficient square hole design, uniform force, smooth punching without burrs, low noise processing and not easy to break. Superb sharpening technology makes the blade sharper and more durable. It's a must for home carpenters.[High quality material] The ferrule drill bit is made of high quality high speed steel, with high hardness, wear resistance, high temperature resistance, longer service life, long recycling term and positioning precise.Wide ApplicationsPerfect for all types of woodworking, carpentry and crafts, construction and maintenance work. * Reminder: the drill seat insert is on a flat surface, which can effectively ensure the resistance of the drill seat and prevent the drill seat from bursting when first used.