Distorted thread locknut: Difference between revisions

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A '''distorted thread locknut''',<ref name="McMaster3139">McMaster, p. [http://www.mcmaster.com/#catalog/114/3139 3139].</ref> is a type of [[locknut]] that uses a deformed section of [[screw thread|thread]] to keep the [[nut (hardware)|nut]] from loosening due to vibrations, or rotation of the clamped item. There are four types: '''elliptical offset nuts''', '''centerlock nuts''', '''toplock nuts''' and '''partially depitched (Philidas) nuts'''.

An '''elliptical offset locknut''' is a [[Nut (hardware)|nut]] that has been deformed at one end so that the threads no longer perfectly circular. The deformed end is usually shaped into an ellipse or [[wikt:obround|obround]] triangle. The nut is easily started on the male fastener as the bottom portion is not deformed. As the male fastener reaches the deformed section it deforms the threads of the nut [[elastic deformation|elastically]] back into a circle. This action increases the friction between the nut and the fastener greatly and creates the locking action. Due to the elastic nature of the deformation the nuts can be reused indefinitely.<ref name="smith">Smith, pp. 104–105.</ref>

==High temperature use==

Because these nuts are solid metal, they are effective in elevated temperature settings, unlike [[nyloc nut]]s. High [[Bolted joint#Property class|grade]] nuts are good up to {{convert|1400|F|C|abbr=on}}. High strength elliptical offset nuts cannot be used with low strength fasteners because the hard nut will act like a [[tap and die|die]] and destroy the threads on the fastener.<ref name="smith"/>

Because these nuts are solid metal, they remain effective at high temperatures, unlike [[nyloc nut]]s. [[Bolted joint#Property class|High-grade]] nuts can withstand temperatures up to {{convert|1400|F|C|abbr=on}}.

==Safety factors==

Cleveloc, a popular brand of oval lock nut, is a registered trade name of Forest Fasteners.

Because these nuts are solid metal, they are effective in elevated temperature settings, unlike [[nyloc nut]]s. High [[Bolted joint#Property class|grade]] nuts are good up to {{convert|1400|F|C|abbr=on}}. High -strength ellipticaldistorted offsetthread nuts cannot be used with low -strength fasteners because the hard nut will act like a [[tap and die|die]] and destroy the threads on the fastener.<ref name="smith"/>

==Elliptical offset nuts==

AnElliptical offset nuts is a catch-all category that encompasses designs known as '''ellipticaloval offsetlocknuts'''<ref name="McMaster3139"/> or locknut'''non-slotted ishex alocknuts''',.<ref>{{Citation [[Nut| title = Non-slotted hex locknut (hardware)|nut]] url = http://www.spstech.com/aero/products/nuts/non-slotted-hex.html | accessdate = 2008-11-30 | url-status = dead | archiveurl = https://web.archive.org/web/20110513080637/http://spstech.com/aero/products/nuts/non-slotted-hex.html | archivedate = 2011-05-13 }}.</ref> The salient feature is that the thread has been deformed at one end so that the threads are no longer perfectly circular. The deformed end is usually shaped into an ellipse or [[wikt:obround|obround]] triangle. TheThese are known as '''one-way''' nuts as the nut ismay be easily started on the male fastener asfrom the bottom non-deformed portion but is notpractically impossible to start from the deformed end. As the male fastener reaches the deformed section it deformsstretches the threads of the nut [[elastic deformation|elastically]] back into a circle. This action increases the friction between the nut and the fastener greatly and creates the locking action. Due to the elastic nature of the deformation the nuts can be reused indefinitely.<ref name="smith">Smith, pp. 104–105.</ref>

==Centerlock nuts==

Center lock nuts are similar to elliptical offset nuts, except that they are distorted in the middle of the nut. This allows the nut to be started from either side.<ref name="McMaster3139"/>

==Toplock nuts==

Toplock nuts are also similar to elliptical offset nuts, except that the whole thread on one end is not distorted. Instead only three small sections of the thread are deformed on one end.<ref name="McMaster3139"/>

==Partially depitched nuts==

Partially depitched nuts are commonly called [[Philidas]] nuts,<ref>{{Citation | title = Philidas nut | url = http://www.philidaslimited.co.uk/home.html | accessdate = 2012-12-01 | url-status = dead | archiveurl = https://web.archive.org/web/20150307180443/http://www.philidaslimited.co.uk/home.html | archivedate = 2015-03-07 }}.</ref> after their originator and current manufacturer, and differ from the above three nut types insofar as a portion of the thread is displaced axially, this being facilitated by one or more slots perpendicular to the axis.

==See also==

*[[Split beam nut]]

==References==

===Notes===

{{reflist}}

===Bibliography===

*{{Citation | title = McMaster-Carr catalog | publisher = McMaster-Carr | edition = 114th}}.
*{{Citation | last = Smith | first = Carroll | author-link = Carroll Smith | title = Carroll Smith's Nuts, Bolts, Fasteners, and Plumbing Handbook | publisher = MotorBooks/MBI Publishing Company | year = 1990 | url = httphttps://books.google.com/books?id=A81HmmRCN7YC | isbn = 08793840690-87938-406-9}}.

{{Nuts (hardware)}}

[[Category:FastenersNuts (hardware)]]