Light duty drill chucks are suitable for small bench drills or hand drills, heavy duty drill chucks are suitable for drilling pressesInstructions for use: 1. The self-tightening drill chuck does not need to be tightened with a wrench. After the cutting tool is installed, the drill chuck jacket is tightened by hand, and the clamping force increases with the increase of cutting force. 2. The drill chuck cannot be used when the machine tool is reversed, and it loses its self-tightening effect when it is reversed. 3. When installing the drill chuck, wipe the taper hole and the taper shank of the machine tool (or electric drill) clean, align the cone with the center of the taper shank and tap the front face of the drill body with a hand or a wooden hammer until it is installed properly.