General description This 4pcs Woodworking Square Hole Drill Bit Kit is designed for carpentry, construction, and decoration industries. It includes drill bits that create square holes in wood, making it an essential tool for any woodworking project. Technical specifications Square Hole Sizes: 1/4 inch (6.4 mm), 5/16 inch (8 mm), 3/8 inch (9.5 mm), 1/2 inch (12.7 mm) Clamping Shank Diameter: 19 mm (0.75 inch) Material: High-quality metal with high strength and hardness Compatibility and accessories Compatible with mortising machines or mortising attachments Package includes: 4pcs Square Drill Bit (other accessories not included) Usage Ideal for drilling square holes in wood Reduces labor intensity and accelerates construction speed Other information Note: Other dimensions are shown in the picture Please avoid 1-2 mm errors due to manual measurement