Breynet Woodworker Square Hole Mortise Chisel Drill Bit Tool Set Kit for Wood, Woodworking Hole Saw Mortising Chisel Drill Bit Set Attachment for Drill Press 1/4" 5/16" 3/8" 1/2" 9/16" 5/8";

Clamping shank diameter: 19mm (Round)

â–² Professional wood drill bit, suitable for construction, installation, renovation, decoration industry, etc.
â–² 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 head wall, a one-time processing of a square hole, and the dust can be broken slag discharged from the tube.

Note:

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.