Woodworking Drill Square Hole Bit Chisel Mortising Kit Mortise Tenon Wood Tool Machine Hole Drill Feature: Professional wood drill bit, suitable for construction, installation, renovation, decoration industry, etc. The utility model in the hole drilled by the rotary body, while the impact of the use of hammer impact force transmitted to the outer, body the material crushing round hole and square headwall, one-time processing of a square hole, and the dust can be broken slag discharged from the tube. Made of high-speed steel. Heat treatment, HRC48~50, high hardness, lengthened core, high concentricity. Great for drilling square holes in wood with a mortising machine or a mortising attachment. Fits all mortising machines and drill press attachments. It will get a double effect by matched use with mortise and tenon machine. The square hole punching needs to use electric drills, hammer u0026 other tools. Reduce the labor intensity of construction workers, speed up the construction speed, reduce construction costs for construction, installation, renovation, decoration industries. Specification: Material: High-speed steel Size: 1/4 inch (6.35mm),5/16 inch(7.94mm),3/8 inch(9.5mm),1/2 inch (12.7mm) Color: Silver Note: Please allow 1-3cm difference due to manual measurement. Due to light and screen difference, the items color may be slightly different from the pictures. Package Included: 1x Square Hole Chisel Mortising Drill