Since the workpiece itself rotates on lathes, the clamping element used must also rotate. So-called chuck parts are held in lathe chucks that enable the workpiece to be clamped centrally on the inside and outside diameter. In most cases, the chucks are equipped with three clamping jaws - depending on the geometry and wall thickness of the part, also with four, six or more clamping jaws.
The workpiece holders are divided into manually operated manual chucks and power chucks, for example hydraulically operated. Power chucks provide excellent clamping force even at higher speeds: By converting the pulling force of the cylinder into a movement of the wedge bars, the centrifugal force is compensated. In comparison, chucks work in the lower clamping range, but create more powerful clamping - even with thin-walled workpieces. Here, several clamping jaws clamp the workpiece axially. Additional clamping in the radial direction provides more stability.
Segment mandrels also adopt this principle. Compared to lathe chucks, segment mandrels, which clamp with expanded segment bushings, convince with more precise and uniform clamping force results. As with collets, a small clamping range is also evident here.
Both lathe and collet chucks centre and clamp on the circumference. Because of this, it is not possible to machine the workpieces over the entire length in a single clamping. If work is to be done without reclamping, face drivers can be used. In this case, the force is transmitted to the face. For long turning diameters, steady rests, also known as steady rests, provide more stability for the workpiece and reduce vibrations.