I have read, from many sources, conflicting information regarding how much to reduce torque when using anti-seize. Does anyone have a definitive answer on this? I torqued my knuckle bolts with anti-seize to spec, and wondering what I have to re-torque them to (as well as all other nuts/ bolts in the future when using anti-seize). Hopefully I didn't stretch the bolts or threads.
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Torque and Anti-Seize
- Thread starter akxj01
- Start date
hanaxj87
NAXJA Forum User
- Location
- Cincinnati,Ohio
I've used never sneeze for years never thought about this... No problems to report on my junk.
Love the anti- seize ,,the next best thing is PB-Blaster...
Nick
Love the anti- seize ,,the next best thing is PB-Blaster...
Nick
RichP
NAXJA Forum User
- Location
- Effort, Pa
Try the copper based stuff, it's even better.
92DripCherokee
NAXJA Forum User
- Location
- Tampa, Florida
something like a 2/3 reduction.
i torqued my lugs to 75 lbs, down from 100
never loosened yet
the important thing is to use the thinnest possible coating. slathering it on will create a problem
i torqued my lugs to 75 lbs, down from 100
never loosened yet
the important thing is to use the thinnest possible coating. slathering it on will create a problem
heyjpark1
NAXJA Forum User
- Location
- Oakesdale, WA
I think we need some input from 5-90, he is the fastener expert (and an expert on most things, now that I think about it).
wim hoppenbrouwers
NAXJA Forum User
- Location
- Netherlands europe
Hallo Jeepers. It is true that the torque is depending on the surface of the bolt.
You need to reduce 20% when you use MOS2 pasta for antiseize. :rtm: http://mdmetric.com/tech/data1torque.html
byebye BANG!
You need to reduce 20% when you use MOS2 pasta for antiseize. :rtm: http://mdmetric.com/tech/data1torque.html
byebye BANG!
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VAwheeler
NAXJA Forum User
- Location
- SE Virginia
I think the only deffinative answer is that the information will conflict.
I am not trying to be a smart ass but I don't ever foresee an answer being the end all to this discussion.
I am not trying to be a smart ass but I don't ever foresee an answer being the end all to this discussion.
Actually, there *IS* a definitive answer........ but it all depends on the lubricant.
Unless specified otherwise, torque specs are always on dry fasteners. Use of any lubricant will reduce the torque spec, but how much depends on the lubricant. The truly persnickety will observe that the fastener material also matters in the observed reduction.
Now, *THIS* is interesting...... looking through http://www.permatex.com, in the product/lubricants section, the standard anti-seize, copper anti-seize and nickel anti-seize technical data sheets all specify normal torque values.
Unless specified otherwise, torque specs are always on dry fasteners. Use of any lubricant will reduce the torque spec, but how much depends on the lubricant. The truly persnickety will observe that the fastener material also matters in the observed reduction.
Now, *THIS* is interesting...... looking through http://www.permatex.com, in the product/lubricants section, the standard anti-seize, copper anti-seize and nickel anti-seize technical data sheets all specify normal torque values.
5-90
NAXJA Forum User
- Location
- Hammerspace
One more time...
Torque spec given for "clean, dry" threads in the manual, unless otherwise specified.
If another lubricant/coating/treatment is specified in the manual, use that only and nothing else! For modifications to "clean, dry," see below:
Clean, dry - 100% of given value
Threadlocker compound - 100% of given value
PTFE/Teflon paste - 90% of given value
Dry graphite - 90% of given value
Engine oil/chassis grease - 75% of given value
Anti-sieze compound - 50% of given value
The given torque value is designed to achieve a certain amount of "preload stress" in the fastener, which contributes to both clamping force and fastener longevity (a fastener not torqued enough will typically fail before one that is torqued too much.) These modifications are given by various compound/lubricant and fastener manufacturers.
Since most of these compounds provide lubrication to the thread surfaces, the same wrench torque with lubrication would increase preload stress within the fastener, as well as stress on the mating threads. It becomes entirely possible to, say, pull the mating threads right out of a casting this way (for instance, on a cylinder head screw. Don't laugh, I've had to fix it when someone else did it!)
This is particularly true of never-seez - which is why I commonly use it someplace other than on threads (for instance, the tapered section of a tie rod end, a ball joint sleeve, or something like that.) There are some threads I'll use never-seez on - brake bleeder screws come to mind - but that's about it. Given a choice, I prefer to use grease or PTFE on a screw thread, simply because it allows more room for error.
Also, bear in mind that there are some screws that a lubricant is specified for in the manual - two that come to mind are the #11 cylinder head screw (PTFE paste, LocTite PST, or similar) and the harmonic damper screw in the crankshaft nose (engine oil - by extension, chassis grease also works.) As I said, if you have a compound listed in the manual for use on a thread, use that compound and nothing else. There's a reason that it's listed...
Torque spec given for "clean, dry" threads in the manual, unless otherwise specified.
If another lubricant/coating/treatment is specified in the manual, use that only and nothing else! For modifications to "clean, dry," see below:
Clean, dry - 100% of given value
Threadlocker compound - 100% of given value
PTFE/Teflon paste - 90% of given value
Dry graphite - 90% of given value
Engine oil/chassis grease - 75% of given value
Anti-sieze compound - 50% of given value
The given torque value is designed to achieve a certain amount of "preload stress" in the fastener, which contributes to both clamping force and fastener longevity (a fastener not torqued enough will typically fail before one that is torqued too much.) These modifications are given by various compound/lubricant and fastener manufacturers.
Since most of these compounds provide lubrication to the thread surfaces, the same wrench torque with lubrication would increase preload stress within the fastener, as well as stress on the mating threads. It becomes entirely possible to, say, pull the mating threads right out of a casting this way (for instance, on a cylinder head screw. Don't laugh, I've had to fix it when someone else did it!)
This is particularly true of never-seez - which is why I commonly use it someplace other than on threads (for instance, the tapered section of a tie rod end, a ball joint sleeve, or something like that.) There are some threads I'll use never-seez on - brake bleeder screws come to mind - but that's about it. Given a choice, I prefer to use grease or PTFE on a screw thread, simply because it allows more room for error.
Also, bear in mind that there are some screws that a lubricant is specified for in the manual - two that come to mind are the #11 cylinder head screw (PTFE paste, LocTite PST, or similar) and the harmonic damper screw in the crankshaft nose (engine oil - by extension, chassis grease also works.) As I said, if you have a compound listed in the manual for use on a thread, use that compound and nothing else. There's a reason that it's listed...
5-90
NAXJA Forum User
- Location
- Hammerspace
That is interesting. Experimentation in class just about three years ago has borne out the values I've given in my previous post - I wonder when this changed? In order to prevent fastener seizure, you have to lubricate the thing - and never-seez is so damned slippery that there's not a lot of room there...
(Testing consisted of using a tensile stress rig, torquing a 1/4"-20 fastener to a specified value of 25 pound-feet, and treating the threads on matching screws with a variety of compounds and noting the stress curve before failure. The receiving block threads were thoroughly cleaned before the experiment progressed to the next lubricant, and a minimum of five samples were processed dry and with each compound tested. Took me a bloody week - but it effectively bore out the values given, that I'd learned 20 years or so ago.)
I use the Permatex Anti-seize and somehow I missed this. Thank you very much.
Can you please provide your source of information for this statement? I have read the exact same thing from someone else on jeepforum.com, although they did NOT state their source either (he said the torque specs are based on wet numbers). I copied and pasted his statement here:
"All OEM manufacturing installation spec's (torque) are developed with "oiled" fasteners, this is the only way you can maintain the required clamping load and repeatability during the torqueing strategy on the assembly lines.."
His profile states he is a: Retired Supply Quality Manager Ford (Powertrain Components).
Here is the link for the thread I started over there (which includes his comments): http://www.jeepforum.com/forum/showthread.php?t=626860
Thanks.
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SeansBlueXJ
NAXJA Forum User
- Location
- Plainfield Township, PA
My dad used to work in an oil fired power plant. they used the stuff on the injector tips to keep the buildup at bay.
5-90
NAXJA Forum User
- Location
- Hammerspace
Source? Nearly every service manual ever read. And classes I've taken at De Anza (working on my Engine Machining and Engine Performance degrees. Had to find out what I'd missed in the last 25-30 years or so...)
Granted, the "assembly line" environment is going to be greatly different from the "service shop" environment - consistency is going to be key on the line, as is speed in getting things together. And, when something is assembled by a machine (pretty much everything these days,) you have more control over the process. Kinda like the evolution of machining with the progression from manual to NC (Numerical Control) to CNC (Computer Numerical Control.)
The only times I've seen a lubricant called out (and it's most often engine oil, oddly enough,) it's been rare enough to note. We have an example - the crankshaft nose screw that retains the harmonic damper. That is torqued to 80 pound-feet lubricated with clean engine oil. Another example would be cylinder head screw #11 on the 4.0L engine (same position on the 2.46L, but I don't recall the number in sequence) where it is specified to about 10% less than the rest after coating the threads with PTFE/Teflon paste.
In no wise do I mean to disparage what you've heard elsewhere - but the working environs are quite different, as are the basic thrust of what is being done. Service shop work is done one at a time and tested individually, while assembly line work is done in rather large batches (hundreds to thousands at a time) and testing is usually "everything to limited extent, spot-check thoroughly." I could be wrong on that last - but it makes sense.
Kinda like machine tool operation - a manual machine operator is going to figure the job (in a stepwise fashion) in a different manner than a CNC programmer/operator - it's just the way the work is done, and the difference in technique will reflect that (it's the biggest hurdle I had to make, apart from getting used to not turning wheels to make chips.)
Flip to the front of your FSM - I'm willing to bet you'll find a statement to the effect of "Torque specifications given are for 'clean, dry' threads unless otherwise specified."
Hey, thank you very much for your help. I just was wondering where you received the information regarding 'dry torque specs'. So many people make statements without citations, so with something as serious as torque specs i just want to be sure. I certainly don't want my knuckle/ hub bolts to snap or vibrate loose, and lose a wheel at 70 mph. For me, working on MY vehicles is necessary (save $) and some fun, I am not anywhere near an expert mechanic level. I am not a professional mechanic.
People (not necessarily you) often get upset when you ask them to source their statements because I think they believe their intelligence is being assaulted, however citations make for more credible information overall. Ever heard of wikipedia (kidding)? People write bogus stuff on their all the time without sources, and in life in general. I was not intending to offend you, just get accurate information. Also, I've looked through my '01 FSM for whether the torque specs are based on dry or wet and did not see it. I'll go back and read it over again.
Thanks again.
By the way, I noticed you live in San Jose, I used to live in Mtn. View.
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