Durable material Made of wear-resistant high hardness cast aluminum, this square hole drill adapter delivers long-lasting performance and serves as a reliable heavy-duty drilling companion. Quick setup Uses a lockable electric drill chuck for easy and safe installation, saving you time. The screw-locking bracket with square hole simplifies setup and enables optimized performance. Optimal performance Expands the functionality of your electric hand drill. The exposed clamping range width is 20 mm and it is compatible with machines for effortless drilling. Not recommended for table and cordless drills. Precision drilling Designed to pair with high quality tools, it enhances woodworking performance and ensures smooth drilling in round materials or along board edges. Applications - Drill precise square holes in wooden panels for dowel joints or hardware inserts using an electric hand drill. - Create square openings along board edges for connectors or fittings in furniture fabrication. - Modify components in DIY projects that require square holes, with clamping support up to 20 mm.