Square Drill Bit Square Hole Saw 6.4-25mm Mortise Chisel Wood Drill Bit Hole Cutter with Twist Drill Wood Drilling Tool Features: 1. This Mortising Chisel is great for drilling square holes in wood with a mortising machine or a mortising attachment. 2. 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. 3. Mortise and tenon square hole drilled by the terrible + outer sleeve in the middle of the combination. 4. Reduce labor intensity of construction workers, speed up the construction speed, reduce construction costs for construction, installation, renovation, decoration industries. Specification: Type: Square Drill Bit Material: High Speed Steel HRC: 56 Note Please allow 1-3mm error due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package Including: 1pc Square Hole Saw