Why does the clamping ring on a drawbar or spigot develop markings?

Markings or indentations on the clamping ring of the spigot/drawbar are typically caused by the bearings applying pressure during clamping. This is a normal occurrence, especially with newer chucks that operate at the higher end of their clamping force range. It does not affect the performance or integrity of the spigot/drawbar. The clamping ring is a wear component, designed to handle thousands of cycles before any replacement is needed.