
Professional design, ideal for drilling square holes in wood with a mortiser. Fits all power drills and accessories. The square hole drill is mainly used in the wood industry. Material and Size: High speed steel. Heat treatment, HRC48~50, high hardness, extended center, high concentricity; 4 sizes 1/4 (6.35mm), 5/16 (7.94mm), 3/8 (9.5mm), 1/2 (12.7mm). Why choose this item: Reduces the labor intensity of construction workers, at the same time accelerates the working speed and reduces costs. Perfect for construction, renovation and decoration field. Package includes: 1 piece 1/4 (6.35 mm), 1 piece 5/16 (7.94 mm), 1 piece 3/8 (9.5 mm), 1 piece 1/2 (12.7 mm),/ Note: Use a drill, hammer or other tools to punch the square punch. (None of these features are: 1. Professional wood drill bit, suitable for construction, installation, renovation, decoration, etc. 2. The workpiece forms a hole drilled by the rotating body, while the impact force is transmitted to the workpiece on the outside of