<P> In precision work, and in some classes of repetition work, cylindrical workpieces are usually held in a collet inserted into the spindle and secured either by a draw - bar, or by a collet closing cap on the spindle . Suitable collets may also be used to mount square or hexagonal workpieces . In precision toolmaking work such collets are usually of the draw - in variety, where, as the collet is tightened, the workpiece moves slightly back into the headstock, whereas for most repetition work the dead length variety is preferred, as this ensures that the position of the workpiece does not move as the collet is tightened . </P> <P> A soft workpiece (e.g., wood) may be pinched between centers by using a spur drive at the headstock, which bites into the wood and imparts torque to it . </P> <P> A soft dead center is used in the headstock spindle as the work rotates with the centre . Because the centre is soft it can be trued in place before use . The included angle is 60 ° . Traditionally, a hard dead center is used together with suitable lubricant in the tailstock to support the workpiece . In modern practice the dead center is frequently replaced by a live center, as it turns freely with the workpiece--usually on ball bearings--reducing the frictional heat, especially important at high speeds . When clear facing a long length of material it must be supported at both ends . This can be achieved by the use of a traveling or fixed steady . If a steady is not available, the end face being worked on may be supported by a dead (stationary) half center . A half center has a flat surface machined across a broad section of half of its diameter at the pointed end . A small section of the tip of the dead center is retained to ensure concentricity . Lubrication must be applied at this point of contact and tail stock pressure reduced . A lathe carrier or lathe dog may also be employed when turning between two centers . </P> <P> In woodturning, one variation of a live center is a cup center, which is a cone of metal surrounded by an annular ring of metal that decreases the chances of the workpiece splitting . </P>

The following is used to turn very long job between centers on a lathe