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.
Size: 1/4 inch (6.35mm),5/16（8mm),3/8(9.5mm),1/2(12.7mm),9/16(14mm),5/8(16mm)
Material: High Speed Steel
Hardness: HRC 48-50
Clamping shank diameter: 19mm (Round)