Lubricants on Threads

[jaye944]

at the end of the day; you need to know if the OEM advises to use wet or dry.
Majority (if not all wheel nuts) are DRY.

I have first hand expereince that after I had used coppaslip on the threads they over torquesed them using there adaptor. THis ment either they where cross threaded or jammed on so tight that even on a 4 poster lift, 2 guys and impact tools could not get the nuts off and they had to bust the nuts off.

This screwed up my rear wheel bearing.

I did a test as well, when I got home I tried withy 1 nut dry 1 wet, and the wet one needed MORE for the torque wrnch to click.

I also note now my nuts "skip" on the threads so all all buggered up.

BACK in the day I never did that and only assembled dry.

"my" advise is to NOT put anything on the threads (just making sure there clean) and torque up to the correct setting, and only use coppaslip etc on the mating surfaces to stop the faces cold welding, NOT the lugs nuts or threads

IMHO, do or dont do...sup to you

 

[sberry]

Yes,,, did anyone read anywhere to put coppaslip on lugs?

 

[HemiRambler]

I think you mean elastic in your quote from below.

Bolts are essentially rubber bands - holding parts in place due to clamping load. When torqued the "rubber bands" get stretched - this is good. When using torque to yield you are simply getting more stretch (clamping load) for a given sized fastener. IE getting a smaller fastener to clamp as much as a larger one - the cost of this is making the bolts disposable - there's the trade off. Torquing bolts dry - is a crappy way to ensure stretch - that why lube is a good thing - it allows you to more accurately predict bolt stretch. For the guys warning that all your lug nuts are gonna fall off if you use antisieze - what do you think holds your rod bolt nuts from falling off? ARP uses a "special" lube - all super low friction stuff to more accurately produce the proper stretch.

Food for thought anyways.

What these guys are saying about lubricated threads is correct. Mostly. GC has it the closest.

To make it simple: When you tighten a bolted joint, you will get a combination of friction on the threads, mating under head bolt surface, and bolt stretch. The only one that really counts is the bolt stretch.

If the bolt does not stretch (in it's plastic region, normally), your bolt can vibrate loose relatively easily. This amount of stretch is not easily measured, so it is usually set up using torque.

When you tighten a bolt, you have friction, and clamp load. Those are each percentages of the energy that is put into the fastener to create a properly tightened joint.

Now, if you use exactly the same torque, but lubricate threads, your friction goes down, and your clamp load will go up. To a certain point, where you will either break the fastener, stretch the fastener to or beyond yield, or you crush the mating parts.

I have seen this in production environments where all of the sudden they are breaking bolts left and right. Many times it boils down to a different coating on the fasteners themselves. Even a different manufacturer of the supposed same coating and same bolt can vary often.

So, not trying to scare anyone from using a lubricant on fasteners, just know that it does change the clamp load, and if it is set up close to the yield point of the fastener, you can easily break bolts using correct torque.

And yes, I do this for a living..... (hope this makes sense, I have been interrupted like 5 times while typing this)....

 

[Lippyp]

I've been using copper grease on lug nuts for at least 20 years and have never had one back off to any appreciable degree. I have had to deal with nuts that were rusted solid though because they weren't lubed. OK, you probably don't want to use it on a high powered race car but then you're unlikely to have that sat outside in all weathers and maybe not having a wheel taken off for a year between services.

 

[ez-duzit]

I've been using copper grease on lug nuts for at least 20 years and have never had one back off to any appreciable degree...

Any degree would seem unacceptable to me (?)

 

[Lippyp]

I've never had a wheel fall off or found any that didn't still need a wrench to undo them. Only time thats come close to happening was when a garage did the nuts on all four wheels on my Triumph Spitfire up finger tight and ten miles down the road it was like driving a clown car as all four wheels were loose (no copper grease on those!) If copper grease is that bad then surely we shouldn't be using it on anything? The usual internet scaremongering ********. I bet if you ask all of the people on here that do use anti seize on their lug nuts not one will have had a nut come loose.