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.