A lathe center (or center) is a tool that has been ground to an included angle of 60 ° and is used to accurately position a workpiece about its axis.

The primary use of a center in metalworking is to ensure concentric work is produced, this allows the workpiece to be transferred between operations without any loss of accuracy. A part may be turned in a lathe, sent off for hardening and tempering and then ground between centers in a cylindrical grinder. The preservation of concentricity between the turning and grinding operations is crucial for quality work. A center is also used to support longer work pieces where the cutting forces would deflect the work excessively, reducing the finish and accuracy of the workpiece, or creating a hazardous situation. Metalworking is the craft and practice of working with metals to create parts or structures. ... Concentric objects share the same center or origin. ... This article is about a lathe as a tool. ... In computing, hardening is the process of securing a system. ... A tool bit generally refers to a plain High Speed Steel (HSS) tool. ...

A center has applications anywhere that a centered workpiece may be used, this is not limited to lathe usage but may include setups in dividing heads, cylindrical grinders, tool and cutter grinders or other related equpiment. The term between centers refers to any machining operation where the job needs to be performed using centers. This article needs to be wikified. ...

A center is inserted into a matching hole drilled by a center drill. Drill bits are the working end of drill tools. ...

Dead center

Live center (top) Dead center with carbide insert (bot)

A dead center (one that does not turn freely, ie:- dead) may be used to support the workpiece at either the fixed or rotating end of the machine. When used in the fixed position, a dead center produces friction between the workpiece and center, due to the rotation of the workpiece. Lubrication is therefore required between the center and workpiece to prevent friction welding from occuring. Additionally the tip of the center may have an insert of carbide which will reduce the friction slightly and allow for faster speeds. Dead centers may also be fully hardened to prevent damage to the important mating surfaces taper of the taper and to preserve the 60 ° nose taper. Tungsten carbide, WC or W2C, is a chemical compound containing tungsten and carbon similar to titanium carbide. ... In the design of machine tools there is a need for users to be able to quickly and easily install or remove particular cutting bits or other accessories from the powered rotating spindle of the machine tool. ...

Soft center

Soft centers are identical to dead centers except the nose is deliberately left soft (unhardened) so that it may be readily machined to the correct angle prior to usage. While this operation may appear unnecessary it ensures that the required angle is truly concentric to the axis of rotation. It is performed on the headstock center, not on the tailstock.

Live center

A live center (one where the 60 ° center runs in its own bearings) is used at the non driven or tailstock end of a machine. It allows higher speeds without the need for seperate lubrication, and also greater clamping pressures. They are used almost exclusively in CNC lathes as well as for general machining operations.

Pipe center

A pipe center has a larger diameter at the 60 ° taper end. This allows the center to be used in the bore of a pipe (or similar workpiece). While a pipe center ensures the workpiece remains concentric, its main advatage is that it supports the workpiece securely. Thin walled material such as pipes easily collapse if excessive pressures are used at the chuck end, A Chuck is a specialised type of clamp used to hold rotating tools or materials. ...

Cup center

The cup center is a variation of the live center and is used in woodworking to support the softer material around the actual center and prevent the material splitting.

Drive center

A drive center is used in the driving end of the machine (headstock). It consists of a dead center surrounded by hardened teeth. These teeth bite into the softer workpiece allowing the workpiece to be driven directly by the center. This allows the full diameter of the workpiece to be machined in a single operation, this contrasts with the usual requirement where a carrier is attached to the workpiece at the driven end. They are often used in woodworking or where softer materials are machined.