Nuts

[rambojoe]

The stretch is a function of tension and material properties.

No kidding. Ill rephrase-
Stretch is the fundamental goal.
Better? Limited only by the grade of stud and material. I sorta already said that though.

 

[drcampbell]

The stretch is a function of tension and material properties.

And the inevitable non-zero friction on the threads means that there is both stretch and twist occurring.

 

[MD Automation]

Maybe I should have posted this in the Tips and Tricks thread recently but...

For every trailer ball I've ever had for the last 40 years, I always coat the threads with pipe dope. Teflon paste was what I used back in the 70s, when that first started to become a thing. Not talking about Teflon tape, but pipe dope (paste in a jar w/ a brush).

Then after you tighten the nut down, coat the threads again as best you can. The nut will have cleaned much of your first coat off as you ran it up. It will tend to harden and stay on the threads as a poor-man's waterproofing.

If the trailer ball has a bolt that threads up - and no nut - then just coat the bolt threads.

Really does a good job of preventing the inevitable rust that will make those things a bear to take apart after a few years.

I have never had a hard time removing a nut from a trailer ball stud that was coated in pipe dope 10 years down the road.

Just saying - works for me.

Edit - And I would suspect that if the nut ever did start to become loose - it would not run itself down easily at all if it was installed with pipe dope. It would act like some really weak thread locker.

 

[Sea Nile]

Get rid of the threads entirely.

 

[Sberry]

How does it stretch if it sticks and simply stops turning? Even on good threads 40% of the torque is used to overcome thread friction. The friction is a guess at best.
This is kind of why they came up with dry, they cant get people to do it right. The book says,,, lightly lubed threads, next guy figures that means never seize, next decides its pipe dope, next guy greases it. Its really a matter of getting people to do it right so they finally give up. Another few years and we will have a whole generation of stuck fasteners only ratyher recently inbstalled or seized at the time of installation.
I asked some of the engineers that were involved in some of this moere early on in the internet and the answer was,,,,,,,,,,,,,,,,,, some people just wont get it. Its what he said.
They recommend the lube "under the turned element" There are so many terms I cant even remember them all involved in trying to keep the friction at least consistent.
Along with this I read about every book the Cincinatti public library had on it and on prestress and post tension concrete. Most of it was over my head but I could grasp the principle,,, that dry you can never gage what is friction and how much is applied to tension and how much seizure occurs at installation, how much is required to restart, how ruff threads are.
As one post above said,,, they run the thing back and forth which is good, smooths the threads while not under tension.
One reason for wheel nuts dry s not the threads as it is the alum wheels, with steel we want spray but alum with slippery stuff,,, especially anti seized and tapered fit it drives them so tight especially hitting with air gun and actually deforms the hole.

 

[Sberry]

Before all this dry torque,,, I remember doing service install and the inspector who was notorious for bashing home body types looked and commented,,, I like that, could see the care it took to put a dab on.
I studied this a while and it was really somewhat academic so to speak and really didnt hit hard till working with a bunch of steel 2 inch screwed fittings and lots of test fittings and how easy it was to stick them even dry by hand and what a difference the spray made. While we want to seal it one of the main purpose of the thread stuff is lube, some even say it, sealer lubricant so the fitting will get tight and so it can be removed.
Really made some of this stand out with so much impact and car wheels, they zip them and heat and pressure friction weld nuts to studs. Wheels never get clamped. The driver says, nuts came loose,,, no they didnt, still cant turn them, it just didnt clamp the wheel.
This happens a LOT.
I see by some likes,,, and I suspect its simpler and lot of guys agree but simply dont think the argument is worth it but this has now become recent lore,,, I cant figure out exactly how and why but like so many myths partly true, not in all cases etc but this is something should have been or should be required in trades course work and despite millions of fasteners we now have 5 minutes of instruction about everything that holds the world together,,, which is simple,,, dry and torque and move on from there to ,,, and then the problem come up and 5 more minutes paid to the fix by adding another tool with minimal instruction again.

 

[Sberry]

The pipe dope scenerio wasnt that it set the nut,,, it was that it simply allowed the nut to tighten. We had loose ball the other day also, clasic case of not following instruction by someone going to do the exact opposite no matter what he is told. 15 minutes of operation, ball is loose and nut 1/2 the way off and I asked, did you lube and use big wrench,,, no, didnt spray it, I install it and 2 days and doesnt come loose. Was able to drive it so much tighter.
Get a keg of building bolts, have special spray on them, just a bit to avoid corrosion and to keep them from seizing when driven with impacts.

 

[Sberry]

I have never had a hard time removing a nut from a trailer ball stud that was coated in pipe dope 10 years down the road.

No real mystery, allowed it to tighten without galling the treads, didnt allow moisture in. Some turns of black tape on exposed threads will keep the nut from running off after it works loose if that is a concern.

 

[rambojoe]

I like you sberry, yer my kind of feller

 

[retirede]

How does it stretch if it sticks and simply stops turning? Even on good threads 40% of the torque is used to overcome thread friction. The friction is a guess at best.
This is kind of why they came up with dry, they cant get people to do it right. The book says,,, lightly lubed threads, next guy figures that means never seize, next decides its pipe dope, next guy greases it. Its really a matter of getting people to do it right so they finally give up. Another few years and we will have a whole generation of stuck fasteners only ratyher recently inbstalled or seized at the time of installation.
I asked some of the engineers that were involved in some of this moere early on in the internet and the answer was,,,,,,,,,,,,,,,,,, some people just wont get it. Its what he said.
They recommend the lube "under the turned element" There are so many terms I cant even remember them all involved in trying to keep the friction at least consistent.
Along with this I read about every book the Cincinatti public library had on it and on prestress and post tension concrete. Most of it was over my head but I could grasp the principle,,, that dry you can never gage what is friction and how much is applied to tension and how much seizure occurs at installation, how much is required to restart, how ruff threads are.
As one post above said,,, they run the thing back and forth which is good, smooths the threads while not under tension.
One reason for wheel nuts dry s not the threads as it is the alum wheels, with steel we want spray but alum with slippery stuff,,, especially anti seized and tapered fit it drives them so tight especially hitting with air gun and actually deforms the hole.

The simplest rule of thumb is to stop tightening 1/2 turn before the stud snaps off.

 

[ptonsparky]

The simplest rule of thumb is to stop tightening 1/2 turn before the stud snaps off.

Now that, I can relate to. The rest was way over my head.

I hate to say it, I know the nut was on, but I never checked it for snugness at all. Didn't even think about it.

 

[jim dungar]

Making proper electrical connections is not the same as making proper mechanical connections even though both actions involve similar components and tools.

Making proper mechanical connections for structural steel on a pressure vessel is not the same as making proper mechanical connections on an F1 race car, even though both actions involve similar components and tools.

Follow the manufacturers instructions.

 

[zbang]

The book says

Um, which book and what's the application? I'd like to read it.

 

[GeorgeB]

Dont lube machine threads unless you really want them to break free.

Proper torque with proper lube will give proper stretch. IFF proper, load cycling will never unload the tension so breaking free would be unusual.

 

[rambojoe]

Proper torque with proper lube will give proper stretch. IFF proper, load cycling will never unload the tension so breaking free would be unusual.

Proper torque with a proper understanding of mechanical physics will be different from what you accept. Educate yourself. It will make you a better man.

 

[mtnelect]

WD-40

 

[rambojoe]

WD-40

On mains, above buss ducts! Bravo! Dare i say tallow or 0w30?

 

[rambojoe]

Btw, if we saw lube on axle bolts or anything immediately visable on your vehicle at the track we would send you home...

 

[TwoBlocked]

Had a tow behind lift pop off the ball once (no real damage, and yes it was the right sized ball). Lever was down and locking pin was in place, but the tongue had never actually been engaged on the ball. I asked around how you could ever be sure it was engaged, then? Answer - After you latch the ball in place, use the jack to try to raise it again off the ball.

 

[Sberry]

Um, which book and what's the application? I'd like to read it.

Snapon torque wrench manual, been there for decades. From when they invented the tool.

Proper torque with a proper understanding of mechanical physics will be different from what you accept. Educate yourself. It will make you a better man.

I think George is a legitimate engineer?

Btw, if we saw lube on axle bolts or anything immediately visable on your vehicle at the track we would send you home...

I bet that is a crew of well informed well studied group of experts, part time racers?

Educate yourself. Ever read a book on this?