General description These 4-Pack Square Hole Drill Bit Sets are designed for woodworking, allowing you to drill precise square holes in wood. Made from high-speed steel, these bits are durable and practical, featuring heat treatment for a long service life. 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) Compatibility and accessories Used with a mortising machine Can be used manually with a hand drill and hammer for square hole drilling 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, lowering costs in construction, installation, renovation, and decoration industries