proper way to use a lock washer?

When using a nut, lock washer and bolt, should you also use a flat
washer between the object and the lock washer? I have seen it done
a million times that way but it seems the flat washer defeats the
purpose of the lock washer. I assume the lock washer is there
to dig in a bit to the object and the nut to keep it from
loosening. The flat washer seems like it would allow the
lock washer to rotate without digging in to the object.
Anyone know?
Reply to
asdfasdf
Loading thread data ...
formatting link

Reply to
PrecisionmachinisT
Wikipedia ruins everything. I was expecting a big argument to start.
Reply to
asdfasdf
Well, I'd say it depends...for instance, a soft washer with a large diameter (fender washer) likely would provide more friction against the material being bolted and so I have to at least partially disagree with wiki on this..
Reply to
PrecisionmachinisT
It depends on the need.
If you are locking a nut to the base metal it is locking to - use s star / split / double star / spring etc then the nut or a washer and a nut. The washer spreads the presser across the nut and allows it to rotate freely.
If you are trying to lock the nut and the thread then you are trying to put side pressure on the nut....
Sometimes it is two nuts together with a washer.
Many uses.
Martin
>>> When using a nut, lock washer and bolt, should you also use a flat >>> washer between the object and the lock washer? I have seen it done >>> a million times that way but it seems the flat washer defeats the >>> purpose of the lock washer. I assume the lock washer is there >>> to dig in a bit to the object and the nut to keep it from >>> loosening. The flat washer seems like it would allow the >>> lock washer to rotate without digging in to the object. >>> >>> Anyone know? >>> >> >>
formatting link
>> >> >> > > > Wikipedia ruins everything. I was expecting a big argument to start.
Reply to
Martin Eastburn
Despite what wiki says, I frequently use (and see used) a split lock washer between a nut/bolt head and a flat washer. Even though it isn't going to "bite" into the object being held or the nut/bolt head, it still provides a longitudinal force to help keep it from becoming unfastened.
Jon
Reply to
Jon Danniken
It may be worth a more extensive search. A mechanical engineer I know, whose a very sharp guy, told me that someone did a study and determined that split washers work because they act as springs that keep the tension on the threads in one direction.
Wikipedia is not always a reliable source.
Reply to
Tim Wescott
There are numerous views regarding the in/effectiveness of split style lockwashers.
One sure way to be certain is to use the proper Loctite or similar thread locking product. Another option is to use nylock or other types of self-locking nuts.. although this may be more costly than threadlocking products, and some types are considered OTU one-time-use only.
Reply to
Wild_Bill
Then edit the page so that it is more reliable...
Reply to
Richard
Some simply consider split ring washers to be the work of the devil.
I found this looking for a more extensive set of videos of bolts loosening, and the test rig used.
formatting link

formatting link

formatting link

Reply to
spamTHISbrp
...
I didn't watch the rest; I notice they didn't say anything about the torque applied on the test. Didn't appear to me it was more than just "snugged down" rather than really torqued, but who's to know--they cleverly didn't the applicator so can't even judge by looking the amount of effort or size of ratchet, etc. While it may have been optical delusion, looked to me like the bolt turned as well which wouldn't indicate being very tight.
I don't have any scientific evidence but 50+ yr practical use on farm indicates to me they serve a useful purpose.
Reply to
dpb
I was impressed by this test at first, but then I realized looking at the graph (
formatting link
) that the major difference occurs only after the bolt is already too loose. The plots diverge only after the bolt has already lost half its preload. They really need to concentrate on the very first part of the curve where the bolt starts to loosen. If you look closely, there is some indication one curve is much steeper than the other at the start, but it is impossible to tell which it is. Maybe they need to dial back the shaking a bit to be able to measure that part of the curve better.
Reply to
anorton
(following up to my own post) What would be best would be to create a set of curves like this at several vibration amplitudes and see if there is some level of vibration where the lockwasher prevents any loosening, but the plain nut does not.
Reply to
anorton
Would you be happy if I quoted Aristotle, quoted the Bible, and then called you a bad name? I'd sure not want you to leave the room unsatisfied, and all. . Christopher A. Young Learn more about Jesus
formatting link
. .
formatting link
hers
Wikipedia ruins everything. I was expecting a big argument to start.
Reply to
Stormin Mormon
I'm not a reliable enough source, either. I was advising the OP to look around and make up his own mind, not to believe what I said without question.
If I needed to know I'd do a literature search -- starting, I admit, by looking up my old mechanical engineering colleague, to see if he could remember where he saw the note (I think it was NASA tech briefs. NASA was doing all sorts of studies in that vein for a while).
Reply to
Tim Wescott
That's the rcm way! I was hoping someone would do my thread justice.
Reply to
asdfasdf
The Book of Gunner (in the Old Testament; one of the lost books) relates: 4. And at the early moment of dawn, on the sixth day of the week. The chariots were heard in the distance. My best look out came back into camp, and reported that the enemy had amassed 500 chariots with warriors and boys to assist. 5. My look outs from the high towers reported that behind the chariots were amazing multitudes of busty and nubile women, both nobles and wenches, and girls too young to have been married off to the warriors of the opposing realm. And they had heard that I, Gunner, was legenday and unstoppable in the bedroom, after having bilateral angio venoplasty paid for by the tax payers of California, to treat my years of self inflicted cigar smoking and drinking of whiskey. 6. I called heartily with booming and resonant voice (only coughing a couple times account of the cigar) to my trumpeter, to rally my men, to sound the charge. We had only 200 chariots with warriors, boys, and small number of busty women, the remainder of the women were slumbering in exhaustion after the bedroom epic drama of last night. 7. My chariots went into battle, and the fight was extreme. In the heat of the battle, the opposing chariots wheels all came off, as if on signal. Mine rallied and fought to the end, as I had used my lathe, and hydraulic stamping press to generate suitably sized lock washers, to hold the wheels on. (Can be seen, item #2814, on 55 tools blogspot, hosted by Rob H.)
Aristotole say (or was it Confucious) man without lock washer have loose nuts.
You misspelled your screen name, asshat. . Christopher A. Young Learn more about Jesus
formatting link
. .
That's the rcm way! I was hoping someone would do my thread justice.
Reply to
Stormin Mormon
Which lubricant should be used on thread, when tightning a bolt, nut, and lock washer? I'd think that something with WD-40 would be used. Everyone knows that WD-40 was designed as a lubricant. Right, asshat? . Christopher A. Young Learn more about Jesus
formatting link
. .
That's the rcm way! I was hoping someone would do my thread justice.
Reply to
Stormin Mormon
Most of the applications I have, I'd go with farm experience rather than a web site that claims this or that.
Do you ever stack a lock washer and flat washer? And, how does that turn out? . Christopher A. Young Learn more about Jesus
formatting link
. .
I don't have any scientific evidence but 50+ yr practical use on farm indicates to me they serve a useful purpose.
Reply to
Stormin Mormon
...
Quite a lot...a wide variety of applications have adjusting slots for depth settings, etc., that have flat washers to span the slot and lock washer on top. Works fine...
Again, for the application. I can imagine one can find vibration regimes/applications where it doesn't suffice.
Reply to
dpb

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.