General description Five different sizes of long tapered twist drill bits designed for efficient drilling and fast chip evacuation. This set includes high-speed steel drill bits that are strong, heat-resistant, and durable, making them ideal for various applications. Technical specifications Material: High-speed steel Shank size: 1/4 inch (6.3mm) hex shank Compatibility and accessories Universal compatibility with most hand electric drills Includes a hex wrench for adjusting the chamfer position and controlling drilling depth Usage Mainly used for punching and chamfering of various materials including plastic, PVC, rubber, and wood.