Talk:Nyloc nut

Article misnamed? Nut developed by Nylok? (NB "k")

So was the polymer-insert locking nut originally developed by the Nylok corporation? If so, then this article (a) should be renamed into generic name (Trade Name) format, and (b) should revise the spelling from "Nyloc" to "Nylok". — Lumbercutter 20:31, 30 August 2007 (UTC)

Reuse

The nylon insert locknut was developed by Elastic Stop Nut Corp (ESNA) Esna nuts first with a fiber insert for use on aircraft. The insert material was changed to nylon (DuPont Zytel 101) for better performance. The articel is incorrect in stating that the nut cannot be re-used. The nylon insert locknut can be re-used up to 50 times and still provide a locking function. Zytel 101 nylon has a "memory" and tries to return to its original form, with no threads cut into the ring. Thus the nylon insert locknut (NILN) is the best type of locknut to use for vibration applications. Most NILN used in USA manufacturing are made in Taiwan, China, Japan or India.76.16.66.201 (talk) 00:51, 9 February 2008 (UTC)

As I understand it, nyloc nuts can be uninstalled and reinstalled multiple times without affecting the nylon insert, as long as the joint is not preloaded. See for example NASM 25027, SPECIFICATION, NUT, SELF-LOCKING, 250°F, 450°F, AND 800°F, which requires that the running torque and breakaway torque fall within certain ranges for 15 cycles of installation and removal, but defines an installation cycle in terms of 1 to 2 full thread protrusion beyond the end of the nut, not in terms of any preload (§4.5.3.3.2). NAS 3350, NUTS, SELF-LOCKING, 450°F AND 800°F, HIGH QUALITY, is similar, and specifically mentions that the installation is unseated (§3.4.1.8). It's possible that preload doesn't affect the locking capability, but none of the standards I'm aware of test for that. And, of course, reuse of a preloaded nut/bolt creates other issues unrelated to the nylon insert. I suggest adding something to that effect to the reuse sentence. Thoughts? Khakiandmauve (talk) 16:27, 3 June 2010 (UTC)

The article does say that they can be reused. I highly doubt that the pre-load of the joint has any affect on whether or not a nyloc nut can be used because the locking element doesn't support any of the load, so it won't be more deformed by a higher pre-load. Wizard191 (talk) 16:49, 3 June 2010 (UTC)

I tend to agree that the locking element won't support much of the load (some, because it's in intimate contact from the start, but it's got a low enough modulus that the threads near the joint should pick up load fairly quickly). But there is disagreement among various sources as to the wisdom of reusing locknuts. http://www.mechanicsupport.com/stop_nut.html gives references to FAA AC43.13-1B, which says yes, and Air Force T.O. 1-1A-8, which says no for critical areas. And regarding reuse of nuts and bolts in general, I don't have a published paper or standard handy, but there's this: http://www.fastenal.com/web/services.ex?action=FEDS&article=Reuse Khakiandmauve (talk) 23:37, 6 June 2010 (UTC)

Those are some good links. I think that in the case of the Air Force they have them switched out because they don't want to take any risks and have an aircraft fail because a locknut was re-used too many times (which is because the mechanic couldn't tell if it was past it usefulness). It would be nice to have a study that showed how nyloc nuts retaining force diminishes vs. number of uses; otherwise we are just conjecturing. Wizard191 (talk) 00:39, 7 June 2010 (UTC)

There's no way the retaining torque is fully maintained during multiple uses! The deformation is NOT purely elastic - just unscrew one and take a look. I suspect that the polymer also creeps, so that the retained torque may also be a function of time. I'm sure the nuts do often remain useful for multiple applications, but most experienced mechanics will have encountered some nuts that unscrew with remarkably little resistance. Please don't re-use them on any aircraft that I'm flying on! —Preceding unsigned comment added by 207.245.198.135 (talk) 11:36, 18 June 2010 (UTC)

Alright then, lets see some reliable references for those statements. Wizard191 (talk) 14:53, 18 June 2010 (UTC)

I think the reference to AC 43.13 is the definitive reference, for civil aviation anyway. As it often does, FAA puts the burden on the user to prove that the condition is safe. They are OK to use *if* the retaining torque requirement is still met. It is up to the user to determine, test and document that the requirements are met -- this being too difficult, most users just toss them if there is any question. Altaphon (talk) 01:26, 22 August 2014 (UTC)

Everyday questions and problems with Nyloc nuts

First, the article should explain, in layman language, what are the advantages of nyloc nuts. Second the article should explain that obviously extra force is required to get the nut deep onto the bolt, starting when the bolt hits the nylon ring. This extra force can easily strip the head of the bolt so it becomes useless. Unless there are huge advantages to nyloc nuts, this renders the nyloc nut useless for non-experts, and they should not be included in self-assembly consumer products.Paulhummerman (talk) 14:15, 4 October 2016 (UTC)

Male parts

This same principle is applied to male threaded parts. agb — Preceding unsigned comment added by 143.43.141.32 (talk) 20:32, 5 May 2017 (UTC)

"Nyloc" is a trademark?

If "Nyloc" is a trademark, and there are non-Nyloc nylon insert nuts, then should this article be more generically named? -- Dan Griscom (talk) 20:00, 19 September 2019 (UTC)

It's a genericised trademark. COMMONNAME supports Nyloc. If anything, we'd expand it to elastic locking nuts in general and include the non-Nyloc forms, particularly the all-metal ones. This would be a much more useful article as fewer, longer articles of more list form (as we have for list of screw drives). But it also needs illustration and sourcing work. As it is, they're all pretty much useless. Andy Dingley (talk) 20:58, 19 September 2019 (UTC)