Description: This is great for drilling square holes in wood with a mortising machine Specification The square hole drill cannot be directly installed on the 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. Arc design, exquisite sharpen durable. Use matters: Square hole drill is mainly used for woodworking aspects. Features: Name: Square Hole Saw Material: Spring steel Color: as picture shows Product size: