Antisieze on lug nuts
01-19-2018, 10:30 AM
#31
RL Community Team
Rennlist Member
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As i mentioned before - dry threads create unreliable frictiona and all toque values when designing a bolt/crew connectionare based on lubricated threads. When too much friction is used the main part of the torque is used to overcome friction and not in reality to load the jount with pressure.
See below from http://www.nord-lock.com/bolted/expe...ing-fasteners/
Q: What happens to preload in the joint during reuse?
A: It is common in many applications to reuse the same nuts and bolts as long as they are in good condition after operation. What happens to the joint preload during reuse is, however, not always considered.
During tightening, metal faces between male and female threads, as well as between the bolt head/nut and substrate, grind against each other causing wear to occur. The result is higher and more scattered friction.
Friction scatter is inherent in every bolted joint upon each installation and can be quite large when installing without any lubrication. When fasteners are reused and tightened to a specific torque, more of the applied torque is required to overcome the friction and less is utilised to obtain the required preload. For each subsequent reuse the preload becomes lower and more inaccurate. This can cause issues when the designer has specified a preload range for the application to maintain sufficient clamp force to overcome the external forces on those joints. Finally, the preload may not be sufficient to withstand the working load applied to the joint, which subsequently fails.
By lubricating the fastener before every use, not only can friction be reduced to improve torque-to-load ratio, friction scatter can also be reduced to improve preload accuracy. The graph here illustrates the torque-to-load behaviour between a dry installation and a lubricated installation. While the preload scatter at a given torque is quite random, you can influence the variability of that scatter by this simple modification.
The prescriptions of the manufacturer regarding lubrication have priority and must be followed. It may be necessary to reduce the torque to avoid damage to the bolt or the clamped parts.
See below from http://www.nord-lock.com/bolted/expe...ing-fasteners/
Q: What happens to preload in the joint during reuse?
A: It is common in many applications to reuse the same nuts and bolts as long as they are in good condition after operation. What happens to the joint preload during reuse is, however, not always considered.
During tightening, metal faces between male and female threads, as well as between the bolt head/nut and substrate, grind against each other causing wear to occur. The result is higher and more scattered friction.
Friction scatter is inherent in every bolted joint upon each installation and can be quite large when installing without any lubrication. When fasteners are reused and tightened to a specific torque, more of the applied torque is required to overcome the friction and less is utilised to obtain the required preload. For each subsequent reuse the preload becomes lower and more inaccurate. This can cause issues when the designer has specified a preload range for the application to maintain sufficient clamp force to overcome the external forces on those joints. Finally, the preload may not be sufficient to withstand the working load applied to the joint, which subsequently fails.
By lubricating the fastener before every use, not only can friction be reduced to improve torque-to-load ratio, friction scatter can also be reduced to improve preload accuracy. The graph here illustrates the torque-to-load behaviour between a dry installation and a lubricated installation. While the preload scatter at a given torque is quite random, you can influence the variability of that scatter by this simple modification.
The prescriptions of the manufacturer regarding lubrication have priority and must be followed. It may be necessary to reduce the torque to avoid damage to the bolt or the clamped parts.
01-19-2018, 10:35 AM
#32
RL Community Team
Rennlist Member
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Whoa,,,,,,! Another thing I need to worry about. Friction Scatter........ YIKES!!!!!
Now you sent me down some rat hole...... where I discovered not only where Friction Scatter lives, but his evil buddies Torque Scatter, Load Scatter, and the most under-examined, Forum Scatter. Forum Scatter is not much understood but generally it relates to what happens on automotive forums when a subject is transformed by scatter-brained posters who scatter hearsay with science resulting in forum members fleeing thus known as Forum Scatter. This entire phenomenon can be summarized by shortening the word to a single short hand expression.... "bull scat"
https://www.enerpac.com/en-us/torque-tightening
https://www.designworldonline.com/el...tener-failure/
http://www.na.henkel-adhesives.com/u...994_LT6734.pdf
Nuggets (aka Nugget Scatter)from links above (yes I do read this stuff)...
"As much as 90 percent of the torque applied to a fastener is used to overcome the friction of the interfacing surfaces." so said the lube mfgr....
Now you sent me down some rat hole...... where I discovered not only where Friction Scatter lives, but his evil buddies Torque Scatter, Load Scatter, and the most under-examined, Forum Scatter. Forum Scatter is not much understood but generally it relates to what happens on automotive forums when a subject is transformed by scatter-brained posters who scatter hearsay with science resulting in forum members fleeing thus known as Forum Scatter. This entire phenomenon can be summarized by shortening the word to a single short hand expression.... "bull scat"
https://www.enerpac.com/en-us/torque-tightening
https://www.designworldonline.com/el...tener-failure/
http://www.na.henkel-adhesives.com/u...994_LT6734.pdf
Nuggets (aka Nugget Scatter)from links above (yes I do read this stuff)...
"As much as 90 percent of the torque applied to a fastener is used to overcome the friction of the interfacing surfaces." so said the lube mfgr....
"Lubrication ..... increases bolt service life"
" Lubricant or anti-seizure compounds should be applied to both the nut bearing surface and the male threads. "
Tune in next week where I will open a discussion, a phenomenon introduced to me by my pissed off wife, Nut Scatter.
Peace
Bruce in Philly
" Lubricant or anti-seizure compounds should be applied to both the nut bearing surface and the male threads. "
Tune in next week where I will open a discussion, a phenomenon introduced to me by my pissed off wife, Nut Scatter.
Peace
Bruce in Philly
Last edited by Bruce In Philly; 01-19-2018 at 11:13 AM.
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808Bill (09-03-2019)
01-19-2018, 01:22 PM
#34
Moral of the story:
Use anti-seize. Or Optimoly. Or oil. Or baby powder. Or mustard.
Or don't.
Torque to exactly 96 ft-lbs. Or to 118 ft-lbs. Or to 110 ft-lbs.
Or until tight.
Your wheels aren't going to fall off.
Gosh we're a pedantic bunch.
Use anti-seize. Or Optimoly. Or oil. Or baby powder. Or mustard.
Or don't.
Torque to exactly 96 ft-lbs. Or to 118 ft-lbs. Or to 110 ft-lbs.
Or until tight.
Your wheels aren't going to fall off.
Gosh we're a pedantic bunch.
01-19-2018, 02:26 PM
#35
Three Wheelin'
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I would say half of us don't give a **** - and half of us try to do it right but in different ways. Both might work just fine unless you are a complete moron when it comes to tools.
Either way - the likelihood that the wheels will fall off is very small. I have had 1 case when a lug bolt fell off after so called professionals did the wheel change. After this I do it myself.
Either way - the likelihood that the wheels will fall off is very small. I have had 1 case when a lug bolt fell off after so called professionals did the wheel change. After this I do it myself.
01-19-2018, 03:06 PM
#36
Instructor
Years ago as a tool and die maker working for Mercury Marine I was involved in calibration of torque wrenches and other torque delivery tools for production of out drives and motors. It was an eye opener to discover how much variations exist in the actual torque value versus the settings on the wrenches. I take the 96 Lb as a ballpark number and apply the silver stuff to aid in removal. I know the stuff allows for more actual rotation and tension on the stud but probably offsets the unknown error of my old torque wrench. I have not had a wheel fall off and have not warped or twisted anything so its perfect for me. And Bruce, I sure hope I can avoid Nut Scatter
06-27-2018, 03:25 AM
#37
Nordschleife Master
I think that a Cu based paste is not right. Porsche recommends Optimoly TA, which is available form the UK in 100g cans here:
http://www.motobins.co.uk/
Enter part number 95805 in the search box. Total cost (PayPal) including shipping is around US$17.
http://www.motobins.co.uk/
Enter part number 95805 in the search box. Total cost (PayPal) including shipping is around US$17.
09-03-2019, 12:21 PM
#38
Rennlist Member
... ... ... 3 pages ! ... ... ... 
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kru911 (09-03-2019)
09-03-2019, 06:26 PM
#40
Rennlist Member
Been using a dap of synthetic grease on my lugs on all my vehicles, Jeeps, Land Rover, Volvo, audi since 1995. Most Jeeps and Land Rover were off-roaded and never ever have I had a problem with a lug coming off or even loosening or anything like that.
Always used a torque wrench and rotated my tires every 6 months.
I did have a problem before greasing the lugs and a shop had to drill the nut and lug off cause a McGuard locking nut was seized in place and its key stripped the "design" on the nut. They tried the universal nut removers that you hammer over the nut, but nothing worked.
That was the end of locking nuts on any of my vehicles and the start of greasing the lugs.
Always used a torque wrench and rotated my tires every 6 months.
I did have a problem before greasing the lugs and a shop had to drill the nut and lug off cause a McGuard locking nut was seized in place and its key stripped the "design" on the nut. They tried the universal nut removers that you hammer over the nut, but nothing worked.
That was the end of locking nuts on any of my vehicles and the start of greasing the lugs.
09-03-2019, 06:58 PM
#41
Rennlist Member
If I have lugs that are way too hard to get off at proper torquing, I ALWAYS throw a good quality synthetic based grease on the threads. If anything, just to coat the threads on either side to not corrode as much or as fast. I have never had an issue with any of my cars in the past 20-25 years of doing this. This also applies to many other nuts and bolts on dirt bikes, mountain bikes, racing kart, road bikes, etc... I've never had an issue. I only use anti-seize on surfaces that are not like in material (aluminum or titanium used on the nuts or bolts. Some call this "ti prep" or "titanium prep" but its basically an expensive anti-seize. If I don't happen to have any ti prep available, I will use the synthetic grease, but it doesn't seem to last as long, but it is MUCH better than nothing, in a pinch. Regarding the Mechanic school, someone mentioned above, like I have been told by another mechanic in the past, "hey man, we aren't doctors or rocket scientists for a reason". Most of the time, I trust myself much more than the "average" mechanic (I have a background in wrenching at a bike shop when I was in college, and grew up fixing my own dirt bikes and BMX bikes). It is the very specialized mechanics, that are the ones that you really want to pay attention to.
09-04-2019, 12:15 PM
#43
I have always used never seize...plain old silver stuff on my 69 911S ..I put it on the convex portion of the nut and on the threads and torque to 95. Of course, the lug nuts are alloy, not steel.
09-04-2019, 04:23 PM
#44
Nordschleife Master
If by convex section you mean the washer's conical surface... you should keep that clean/dry. Optimoly is applied on the threads and the running groove between the washer and the bolt head.
09-14-2019, 07:48 AM
#45
So I saw this thread pop up. Got an Audi Q7 with the same lugs as the Porsche. I have the Audi service manual which has the same recommendations as the Porsche. So decided to take off the wheels to do the lugs on it and the Porsche. Been over a year since had the wheels off the Audi. And guess what...
snapped Ed one of the lug bolts in half. It was frozen/rusted in the hub. Took it to the tire shop and the got it out. Asked them about the paste and they said never. They have had meetings and experts come in and they all recommend against it. But from now on, I’m a paste guy.
snapped Ed one of the lug bolts in half. It was frozen/rusted in the hub. Took it to the tire shop and the got it out. Asked them about the paste and they said never. They have had meetings and experts come in and they all recommend against it. But from now on, I’m a paste guy.