mandrel

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A spindle or an axle used to secure or support material being machined or milled.
2. n. A metal rod or bar around which material, such as metal or glass, may be shaped.
3. n. A shaft on which a working tool is mounted, as in a dental drill.

Century Dictionary and Cyclopedia

1. n. In mech., a cylindrical bar or spindle, either of uniform diameter, of different diameters, or tapered, used for a variety of purposes, but chiefly for the support of objects formed with holes, into which the mandrel is forcibly driven in order to hold them firmly while turning in a lathe, or in an analogous machine, or in operating upon them with a file. Specifically— An axis attached to the head-stock of a lathe, to support, during the process of turning, any material which is bored or pierced with a central hole. It has often some adjustable device for securing it to the material, and is then known as an adjustable mandrel.
2. n. A miners' pick.
3. n. In metal-working by the spinning process, the form, usually of wood, upon which the thin plate of metal or blank is pressed in order that the revolution may give it the form of mandrel.
4. n. A mandrel fitted to a bearing or bearings of a support which may be set in the tool-post of the slide-rest of a lathe, or in some other traversing device. Such mandrels are used for expanding reamers and analogous tools, and they are usually driven by a pulley-and-belt mechanism.
5. To operate upon with mandrels, as a bronze gun. This is done by driving steel mandrels of gradually increasing size through the bore, whereby the strength of the gun is greatly increased, the limit of elasticity being in some cases nearly or quite doubled.

Wiktionary

1. n. An object used as an aid for shaping a material, e.g. bending a pipe without creasing or kinking it.
2. n. A tool or component of a tool that grips or clamps something, such as a workpiece to be machined, a machining tool or a part while it is moved.

GNU Webster's 1913

1. n. A bar of metal inserted in the work to shape it, or to hold it, as in a lathe, during the process of manufacture; an arbor.
2. n. The live spindle of a turning lathe; the revolving arbor of a circular saw. It is usually driven by a pulley.

WordNet 3.0

1. n. any of various rotating shafts that serve as axes for larger rotating parts