A chuck is a device that is used to hold an object in place while it is being worked on. It is usually used in watchmaking and can be either a clamp-style or a three-jaw style. The clamp-style chuck provides a secure grip when the object is clamped in place. The three-jaw chuck is slightly more complex and provides a three-point grip, allowing for more precise control over the object. The chuck is a vital tool for watchmakers, allowing them to make precise adjustments to the movement or components of a watch.
