"no design sets out to intentionally require lock washers" If the joint supports proper bolt torque, then skip the fancy snake-oily stuff.
If the joint is right, that stuff is useless. I cite once again Caterpillar. Terrible vibration is normal, high loads (proper accommodated in the design) are normal, acceptability if failure is non-existent - consider mutli-ten million dollar equipment like a front shovel. You will find no lock washers. This is right way to do it. Adding a lock washer actually harms the long term reliability of a critical joint. The cases where you see one are joints that cannot be set up right or are just "this is how we always did it." A castellated nut is maybe good where you don't want to pull a taper too tight. If you have to clamp over a plastic deforming material, a nylock is nice. But these are all sub-optimal solutions. Please understand the difference between a soft elastic metal, and a material that is is plastic in its behavior. You can depend even on lead, tin and antimony to support a high clamping load, and certainly aluminum. Wherever the threads are, if they have enough engagement and you can torque the fastener sufficiently the joint is golden. I really don't care what anyone else does with this information. But, don't think you are doing anything but getting marketed/suckered. This is not an argument for fun or I would have quit long ago, I am trying to be helpful. Save you money, or keep you from failing in the field. Please do as you wish. On Mon, Jan 13, 2014 at 11:26 AM, Evan Tuer <[email protected]> wrote: > On Fri, Jan 10, 2014 at 5:58 PM, Michael Ross <[email protected] > >wrote: > > > Yes Evan, you have it exactly right. The popularity of lock washers is > > without merit. I will give you a caveat though, I am talking about > joints > > where there is all metal in the sandwich. More detail below on > > non-metallic stuff. > > > > I believe you are wrong about the Toyotas at leas with all metal joints. > > Tie rod ends are not castellated on my car, they are big and torqued > hard > > with a tapered fit that really does the work. There is no thread locker > > that I have seen, and no nylocks. If you show me I will believe, but I > do > > my own wrenching and have not seen any. I have seen some deformed nuts > > where they whack the end of the nut into an ellipse for use on exhaust > > stuff that has extreme thermal cycling). There are things like battery > > hold downs - not an all metal joint, but I am pretty sure even these are > > not nylock or deformed. > > > > I've never owned a Toyota but I am surprised about that. Certainly every > other car make I've ever worked on, it holds true. > > > > > You are right to press me on this - Why on earth are there all these lock > > washers used? Why do so many people think they are useful? Heck, > Nordlock > > may be quite sincere in thinking their fancy washers do something. Part > of > > this is tradition that is self sustaining - they are everywhere so the > must > > be good, right? Also, lock washers do get applied places where, > > unfortunately they help, because of design flaws (usually material > > selection). In every case they are a bandaid for a joint that could have > > been better, but maybe cost too much better, or there wasn't time to do > > better, and besides, everyone uses them, right? > > > > You're right, no design sets out to intentionally require lock washers, but > y'know, stuff happens. It's not a perfect world and sometimes other > factors such as cost or weight have a higher priority - you can call this > bad design if you like but it seems a bit pedantic. So yes, they're a > bandaid, but they do serve a purpose. > I've worked on heavy equipment in the past (including Cat / Timberjack > stuff) and I can tell you that if they don't come from the factory with > Nord-Locks on certain cover plates and the like, they certainly end up that > way after it all rattles loose after a few hours in service. > > > > > That does not change the fact that a split lock washer, or a Nordlock > is a > > waste of money in a joint that is tight enough not to come loose. And > you > > can design or modify joints so they don't come loose. > > > > Yes you can, but it's far easier and cheaper to add a lock washer or spring > washer than go back to the drawing board. Are you really going to be able > to re-engineer a Chinese lithium cell so that it no longer has a critical > joint made of two soft metals secured with a single small bolt, threaded > into aluminium? > > Having given it further thought, slackening of the joint is likely to be > the concern in this application rather than spontaneous loosening (in most > car applications, I don't think there's enough or the right sort of > vibration to cause the bolt to undo). And the spring washer is there to > deal with the slackening. Leaving it out or changing to a lock-washer (or > thread-lock) alone is asking for trouble IMHO. > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140113/43973074/attachment.htm > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. 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