<P> A revolving center, also known as a live center in some countries, is constructed so that the 60 ° center runs in its own bearings and is used at the non-driven or tailstock end of a machine . It allows higher turning speeds without the need for separate lubrication, and also greater clamping pressures . CNC lathes use this type of center almost exclusively and they may be used for general machining operations as well . Spring - loaded centers are designed to compensate for center variations, without damage to the work piece or center tip . This assures the operator of uniform constant tension while machining . Some live centers also have interchangeable shafts . This is valuable when situations require a design other than a 60 ° male tip . A live center, which may be hard or soft, is a plain center placed in the revolving mandrel; it moves and is therefore live . </P> <P> A pipe center, also known as a bull nose center is a type of live center which has a large diameter conical nose rather than a sharp point . This allows the center to be used in the bore of a pipe or other workpiece with a large interior diameter . While a pipe center ensures the workpiece remains concentric, its main advantage is that it supports the workpiece securely, and can be used for parts whose larger inner diameter prevents the use of a normal pointed center . Thin - walled material such as pipes easily collapses if excessive force is used at the chuck end . </P> <P> There are two types of cup centers . The woodworking variety is a variation of the traditional live center . This type of cup center has a central point like a normal live center and also has a ring surrounding it . The ring supports the softer material around the center point and prevents the wood from splitting under pressure from the central point . A different variety of cup center is used for metalworking . The metalworking variety of cup center has a tapered hole rather than a conical point . It supports the part by making contact with the outside diameter of the end of the part, rather than using a center hole . </P> <P> A drive center, also known as a grip center, is used in the driving end of a machine (headstock). It is often used in woodworking or where softer materials are machined . </P>

Difference between live centre and dead centre in lathe