General description Professional design ideal for drilling square holes in wood with a mortiser. The square hole drill bit is mainly used in the woodworking industry, perfect for construction, renovation, and decoration projects. Technical specifications Material: High speed steel Heat treatment hardness: 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 Reduces labor intensity of construction workers Speeds up construction processes Reduces costs Other information Scope of delivery: 1 piece of each size (1/4", 5/16", 3/8", 1/2") The punch square must use a drill, hammer, or other tools (none included)