General description Professional wood drill bit set designed for construction, installation, renovation, and decoration. This set includes square hole chisels that create both round holes and square heads simultaneously, efficiently discharging dust through the pipe. Technical specifications Material: High speed steel Heat treatment: HRC48~50 Sizes: 1/4 inch (6.35 mm), 5/16 inch (7.94 mm), 3/8 inch (9.5 mm), 1/2 inch (12.7 mm) Compatibility and accessories Suitable for all machines and drill attachments Usage Ideal for drilling square holes in wood Reduces labor intensity and accelerates work speed Perfect for construction, renovation, and decoration