Mandrel

Mandrel
Old shop-made mandrel for turning hollow objects on an engine lathe.
Rotary tool mandrel with an accompanying grinding wheel.
Pulley-driven mandrel used to hold lawn tractor cutting blades.

A mandrel (play /ˈmændrɨl/; also mandril or arbor) is one of the following:

  • an object used to shape machined work.
  • a tool component that grips or clamps materials to be machined.
  • a tool component that can be used to grip other moving tool components.

Contents

Variants

An example of one type of mandrel is a shaped bar of metal inserted in, or next to, an item to be machined or bent in a certain pattern. Exhaust pipes in automobiles are frequently bent using a mandrel during manufacture. The mandrel allows the exhaust pipes to be bent into smooth curves without undesirable creasing, kinking, or collapsing. Molten glass may be shaped in this way as well. Another example of this type of mandrel is found in jewelry manufacturing, where ring and bracelet mandrels are used to shape metal into a desired size and shape, using a tiny hammer to beat the metal against the mandrel.

Another type of mandrel is the clamp that a lathe uses to hold pieces of wood, metal or plastic to be machined as they are turned. In this way, rods can be threaded, furniture legs are turned to have beautiful patterns, and irregularly-shaped objects can be given a cylindrical or round shape. There are several types of mandrels used with lathes. An expanding mandrel is slightly tapered with a tapered wedge that will expand to hold the item. Other commercial mandrels are very slightly tapered and the hollow object slides down the taper until it 'sticks'. The shop-made mandrel shown in the photo is designed to clamp a hollow tube or gear between the two tapered plugs. There is nothing about such a mandrel that can't be made right on the lathe on which it is to be used so it is not uncommon for machinists to make a mandrel to hold a particular item, and then set the mandrel aside hoping to use it again some day. Mandrels of this type are usually set in the lathe on centers and turned with a lathe dog.

The third type of mandrel discussed here is that which is used to hold circular saw blades, buffing wheels (used for polishing), and sanding discs onto drills, circular saws, and similar power tools. A mandrel of this type generally consists of a cylinder, threaded on one end, with a washer brazed onto the threaded end and an accompanying screw and second washer which are used to clamp the circular saw blade, sanding media, or other rotary tool onto the mandrel.

While most mandrels are driven by direct connection to an electric motor or engine, other mandrels are driven by attachment to a bearing-supported, pulley-driven shaft.

Uses

In fiber optics, an optical fiber is often wrapped around a mandrel to alter the light traveling in the fiber.

Mandrels are also used in industrial composite fabrication such as in filament winding. During the manufacturing process, resin-impregnated filaments are wound around a mandrel to create a composite material structure or part. The structure is cured and the mandrel is removed. One problem with this type of process is that the mandrel can be very difficult to remove once the part has been cured. As a result, engineers have created a new type of mandrel that has the ability to change shape and be easily extracted.[1] When heated above a certain temperature, the mandrel becomes elastic and can be manipulated into the desired shape and then cooled to become rigid again in the new shape. It can then be used in the filament winding process. Once the composite part is cured, the mandrel can be reheated until elastic and easily removed from the cured part. These types of mandrels can be used repeatedly.[2]

In the production of steel core used for flexible drives, the centre wire upon which the subsequent layers are wound is referred to as a Mandrel. This 'centre wire' may itself be composed of either a single wire or layers depending on the sizing of the finished product.

History

Mandrels are not recent inventions. Metal machining utilizing the spinning process has been recorded as far back as ancient Egyptian times. In metal spinning, a wood or metal spinning mandrel is used, the form of which corresponds with the internal contour of the part to be produced. This method securely clamps the raw material and allows for accurate machining into the desired final form. Since the material is clamped internally, there is no interference to the operator from the lathe/mandrel assembly during production.

Also, the traversing mandrel was introduced around the year 1700 AD, and consisted of designing a lathe mandrel that would be able to slide axially in its bearings under the control of the operator, so that components having short lengths of thread could be produced, such as screws. The traversing mandrel was primarily employed by clockmakers and ornamental turners during this era. Eventually this device was superseded by a mandrel-driven device called a leadscrew, which utilizes a train of gears that can be altered as required for the turning application.

See also

References

External links


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Look at other dictionaries:

  • Mandrel — Man drel, n. [F. mandrin, prob. through (assumed) LL. mamphurinum, fr. L. mamphur a bow drill.] (Mach.) (a) 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. (b) The live… …   The Collaborative International Dictionary of English

  • Mandrel — Mandrel. См. Оправка. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • mandrel — miner s pick, 1510s, of unknown origin; perhaps borrowed from Fr. mandrin, itself of unknown origin. Also applied from 17c. to parts of a lathe or a circular saw …   Etymology dictionary

  • mandrel — ► NOUN 1) a shaft or spindle in a lathe to which work is fixed while being turned. 2) a cylindrical rod round which metal or other material is forged or shaped. ORIGIN of unknown origin …   English terms dictionary

  • mandrel — or mandril [man′drəl] n. [earlier manderil; prob. < Fr mandrin < Prov mandre, spindle, winch, beam (of a balance) < L mamphur, a bow drill < IE base * menth , to twirl > ON mọndull, handle of a quern] 1. a metal spindle or bar,… …   English World dictionary

  • mandrel — /man dreuhl/, n. Mach. 1. a shaft or bar the end of which is inserted into a workpiece to hold it during machining. 2. a spindle on which a circular saw or grinding wheel rotates. 3. the driving spindle in the headstock of a lathe. Also, mandril …   Universalium

  • mandrel — mandril mandril n. any of various shafts that rotate or serve as axes for larger rotating parts. [Written also {manderil} and {mandrel}.] Syn: spindle, mandrel, arbor. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • mandrel — noun /ˈmæn.drəl/ a) An object used to shape material being worked. This socket forms the starting point of the piercing operation, enabling the mandrel to center itself on the work. b) A tool component that grips or clamps materials to be… …   Wiktionary

  • Mandrel lathe — Mandrel Man drel, n. [F. mandrin, prob. through (assumed) LL. mamphurinum, fr. L. mamphur a bow drill.] (Mach.) (a) 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. (b)… …   The Collaborative International Dictionary of English

  • Mandrel forging — Mandrel forging. См. Ковка с оправкой. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

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