General description Set of 4 Square Hole Drill Bit Sets designed for woodworking, ideal for drilling square holes in wood using a mortiser or mortising machine. These drill bits are made from high-speed steel, ensuring durability and practicality for various construction, installation, renovation, and decoration projects. Technical specifications Material: High-speed steel Hardness: HRC48-50 Sizes: 1/4" (6.35mm), 5/16" (7.94mm), 3/8" (9.5mm), 1/2" (12.7mm) Installation Used in conjunction with a mortising machine If drilling manually, tools such as a hand drill and a hammer are required Usage Ideal for drilling square holes in wood Standard chip design for easy removal of wood chips, improving drilling efficiency Reduces labor intensity and accelerates construction speed Helps lower construction costs