This is an automatic punch that is used to create a depression in a workpiece. It performs the same function as a normal center punch, but without the need for a hammer. When pressed against the workpiece, it stores energy in a spring, then releases it in the form of a pulse that moves the punch and produces the depression. The impulse supplied to the punch is highly repeatable, allowing for uniform engraving. The small dimple is generally used to mark the center of a point and guides the cutter tip, preventing slippage or deviation that leads to damage. Suitable for punching on steel plates, aluminum, copper, wooden boards and other materials for placing holes. This is also a great tool that you can keep in the car to break windows in case of emergency. Size: The total length is nearly 130mm, the shaft diameter is 12.7mm, and the diameter of the punch head is about 0.6mm. Features: The internal spring structure of the center punch can provide strong impact force for completing steel plates, wood punching, broken windows and other tasks. If you are stuck in the car due to an emergency, you can use this center to break the glass to escape. It is simple and easy to use, and the effect is immediately visible! How to use: Use the heavy head to align the positioning point, hold the handle firmly and press the punch. After the punch is pressed into the shaft for a short time, the strong spring will force the punch to eject, make a notch for each point, no need to cooperate. Tools such as hammers are easy to use. Note: The data is manual measurement, please allow 1-44cm error due to the difference between light and screen, there will be a certain color difference, the specific received in kind shall prevail.