General description Professional wood drill bit set designed for construction, installation, renovation, and decoration. This set allows for efficient drilling of square holes in wood using a mortiser, combining the creation of round holes and square heads in one operation while effectively discharging dust through the tube. Technical specifications Material: High-speed steel Heat treatment: HRC48~50 Sizes: 1/4" (6.35mm), 5/16" (7.94mm), 3/8" (9.5mm), 1/2" (12.7mm) Compatibility and accessories Fits all machines and drill attachments Usage Ideal for woodworking applications Reduces labor intensity and accelerates work speed Cost-effective solution for construction, renovation, and decoration industries Other information Includes: 1 pc 1/4" (6.35mm), 1 pc 5/16" (7.94mm), 1 pc 3/8" (9.5mm), 1 pc 1/2" (12.7mm)