Descriptions: This 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.The standard flute is designed to facilitate the removal of the wood chip and improve the efficiency of drilling. Exquisite blade grinding process, edge is sharper and more durable . Features: 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. Exquisite blade grinding process, edge is sharper and more durable . The standard flute is designed to facilitate the removal of the wood chip and improve the efficiency of drilling. Square hole drill is mainly used for woodworking aspects. Specifications: Material: high speed steel Color: as picture shows Size(Optional): 10mm/16mm Length: 203mm(10mm diameter); 208mm(16mm diameter) Weight:166g Package included: 1 x Square hole drill