• This Mortising Chisel is great for drilling square holes in wood with a mortising machine or a mortising attachment.
• Square hole drill can not be used on an electric drill, drill square holes need to fit a square hole drill drilling (mortise and tenon machine) to use.
• Mortise and tenon square hole drilled by the terrible + outer sleeve in the middle of the combination.
• Reduce labor intensity of construction workers, speed up the construction speed, reduce construction costs for construction, installation, renovation, decoration industries.

            Material: high-speed steel
           Hardness: HRC 48-50
           Size: 1/4" (6.35mm), 5/16" (7.94mm), 3/8" (9.5mm), 1/2" (12.7mm)  5/8"(15.9mm)
           Clamping shank diameter: 19mm (Round)
           Length: 210mm
          Package Included: 1 x Square Hole Drill Bit