wood square hole drill， 1pc HSS Square Hole Saw Mortise Chisel Wood Drill Bit With Twist Drill(22mm)

Mortise and tenon square hole drilled by the terrible + outer sleeve in the middle of the combination. 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 . matters: Square hole drill is mainly used for woodworking aspects. Reduce labor intensity of construction workers, speed up the construction speed, reduce construction costs for construction, installation, renovation, decoration industries. The square hole punching needs to use electric drill, hammer & other tools(All of these are not include)