Mandrel
1359546
198583362
2008-03-16T07:13:19Z
FredrikLähnn
4631411
+iw
A '''mandrel''' ({{pronEng|ˈmændrɨl}}, and also spelled '''mandril'''; in [[American English]] also called an '''arbor''') is either an object used to shape machined work; a [[tool]] [[manufacturing|component]] that grips or clamps [[materials]] to be machined; or a tool component that can be used to grip other moving tool components.
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 pipe]]s in [[automobile]]s are frequently bent using a mandrel during [[manufacture]]. The mandrel allows the exhaust pipes to be bent into smooth [[curve]]s 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 [[finger ring|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.
[[Image:Mandrel3.jpg|thumb|right| Old shop made mandrel for turning hollow objects on an engine lathe.]]
Another type of mandrel is the [[Clamp (tool)|clamp]] that a [[Lathe (tool)|lathe]] uses to hold pieces of [[wood]], metal or [[plastic]] to be machined as they are turned. In this way, [[Rod (shaft)|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]] [[blade]]s, buffing [[wheel]]s (used for polishing), and sanding discs onto [[drill]]s, circular saws, and similar power tools. A mandrel of this type generally consists of a [[cylinder (geometry)|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 [[internal combustion engine|engine]], other mandrels are driven by attachment to a bearing-supported, [[pulley]]-driven shaft.
In [[fiber optics]], an optical fiber is often [[Mandrel wrapping|wrapped]] around a mandrel to alter the light traveling in the fiber.
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 [[Metal spinning|spinning]] [[Process (general)|process]] has been recorded as far back as [[ancient Egypt]]ian 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, costs, and pricing|production]].
Also, the '''[[traversing]]''' '''mandrel''' was introduced around the year 1700 AD, and consisted of designing a [[Lathe (tool)|lathe]] mandrel that would be able to [[slide]] axially in its [[bearing]]s under the [[control]] of the [[operator]], so that components having short lengths of [[screw thread|thread]] could be produced, such as [[screw]]s. The traversing mandrel was primarily employed by clockmakers and [[ornamental]] turners during this [[era]]. Eventually this device was superseded by a mandrel-driven [[machine|device]] called a '''[[leadscrew]]''', which utilizes a [[train]] of [[gear]]s that can be altered as required for the turning application.
==Images==
[[Image:Mandrel 001.jpg|thumb|left|Rotary tool mandrel with an accompanying grinding wheel.]]
[[Image:Mandrel 002.jpg|thumb|left|Pulley-driven mandrel used to hold lawn tractor cutting blades.]]
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==External links==
Historical pictures of mandrels, lathes and leadscrews: http://www.historicgames.com/lathes/special.html
==References==
The Ornamental Turning Center: http://www.turners.org/Articles/lathehistory.html
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[[Verschoyle Patent Mandrel]]
==See also==
*[[Operation Mandrel]]
{{Metalworking - Machine tooling}}
[[Category:Machine tooling]]
[[Category:Tools]]
[[Category:Woodworking]]
[[Category:Lathes]]
[[Category:Clamps]]
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