6-piece Square Hole Drill Bit Set, Woodworking Square Hole Drill Bit Sets, Mortise Chisel & Bit Set, Square Drill Bits for Hole Saw, 6 Sizes

【High-Quality Steel】This square hole drill bit is made of special steel, heat-treated to HRC48-50, offering high hardness, an elongated core, and high concentricity. It features a sharp blade, continuous cutting action, fast cutting, and high efficiency. 【How to Use It】: The rotating body drills the square hole, while the impact force is transmitted to the outer body, grinding the material through the round hole and the square head wall. The debris is then discharged from the tube. 【Labor-Saving and Precise】: This professional mortising chisel is ideal for drilling square holes in wood with a mortiser or mortising attachment. And reduce the workload of construction workers, accelerate construction speed, and lower construction and installation costs. 【6 Different Sizes】: 6 pieces in the package with different slot diameters to meet your needs. Comes with 6 different sizes: 1/10.2 cm, 5/40.6 cm, 3/20.3 cm, 1/5.1 cm, 9/40.6 cm, 5/20.3 cm, suitable for opening various square holes. 【Application】: Fits all mortising machines and drill attachments. Square hole drilling is mainly used for woodworking. Professional tip, suitable for construction, design, renovation, decoration, etc. Caution: The chisel alone does not work in a wood drill; you need an attachment for your drill.