Anti-sieze on head nuts- yes or no?

It's known as " friction co-efficient "in the Oilfield anyway
Used for torque values when making up casing with lubricant applied to it.
 
Wish I saw this before yesterday. Was just putting new stud nuts on my 39 flathead. On one side everything went well, started at 15lbs then 30lbs and ended at a torque of 45lbs. On the other side the 6th nut stripped on the stud. Now the nut just spins on the stud. I used a little anti seize on the theads. I sure hope it is just the nut and the stud that stripped and not the block thread. Later
 
VeryTangled said:
Hi Everyone,

Well, It undoubtedly makes it easy to take apart later, but it can also change the tightening values and the grounding effects as the anti-sieze is an insulator.

Modern manufacturers sometimes caution against using it on spark plugs because it inhibits grounding.
-VT/JeffH
Click to expand...

Jeff, do you have a link that explains that?

My dad and I always put AntiSieze on battery posts on our tractors to stop corrosion, we never noticed an issue.

Now this was the "silver colored" AS...maybe a difference?
 
Based on experience with aircraft jet engines and stationary gas turbines where dry threads are specified. I prefer to stay wth dry threads on the torque side. The simple explaination is that with lubrication, basicly anything wet, you do away with the friction which is actualy part of the specified torque of the threaded connection. It will work as a brake under torquing, and also later prevent unwanted loosening. The first piont MIGHT prevent actually overtorquing the threads with the torque meant for dry threads and a certain friction surface under nut and/or washer. This is specially true when subject to continious on/off and retorque cycluses under extreme condition ofcourse, but the theory is still the same. With the need for sealing threads in the UNC end towards water i use permatex, and with exhaust studs i use anti sieze though, as my cars are not planes. Yet. :)
 
Reading every post in this thread highlights two contentious areas. First off... many flathead people whose opinions and knowledge I greatly respect are advocating a head nut torque of 45 lbs, yet all the old manuals, the Ron Bishop book etc, etc are stating 55lbs.
Secondly.... the same people are advocating a thin smear of oil under the nut to prevent galling against the head, yet other, even within this thread, are advocating dry assembly.
Personally I put Permatex anti-seize on my studs, but not on the threads, and a tiny smear of oil on the bottom of the nuts. I have three heli-coiled studs and they work perfectly, in case anyone wants to know.
 
Bassman/NZ said:
Reading every post in this thread highlights two contentious areas. First off... many flathead people whose opinions and knowledge I greatly respect are advocating a head nut torque of 45 lbs, yet all the old manuals, the Ron Bishop book etc, etc are stating 55lbs.

I was always told 45 lbs for aluminum(aftermarket finned style) heads. And 55 lbs for stock cast iron. Lets see what others say.
Torchie.
Click to expand...
 
Hi Everyone, Mike B, Post #24, here's something from NGK, I didn't see any other manufacturers, but I didn't look hard. This is in reference to modern aluminum heads.

Interesting language on the last paragraph of the first page, sounds like it's from the marketing department, not the tech guys.

"NGK recommends only using spark plugs with metal plating on all aluminum head applications to prevent damage to the head and plug. Metal shell plating acts as a “lubricant” which breaks away from the main body of the spark plug during removal, preventing damage to the spark plug and or threads in the cylinder head."

http://www.ngksparkplugs.com/pdf/tb-0630111antisieze.pdf

-VT/JeffH
 
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Thanks Jeff...for sure I understand the ability to over tighten things applied with anti seize,

I guess I over quoted you though, my question was more to the "grounding effects" of using AS.

I know that using teflon tape can sometimes inhibit continuity, but hadn't heard that AS could as well.
 
Hi Mike B, It's likely that I misunderstood why NGK was giving the recommendation. I can't say that I have any facts to back up my earlier statement, likely it was hot air! :confused:

-VT/JeffH
 
Just to expand on the non-conductor issue, there is or was at least, an anti-seize that was mica based. I have a one pound tin of it and I think it is from the '50's. It has specification AN-VV-C-566, Amendment 1 on the can. On the back is the following notation: "This material, being a non-conductor and possessing a high heat resistance is particularly suitable for use on aircraft engine spark plugs. Due to it's electrical insulating properties, however, it should not be used where mating parts are required to be in good electrical contact."
Seems contradictory, how about the grounding lost if this stuff is a non-conductor?
As far as other anti-seize goes most are molybdenum or copper based and are a conductor.
 
As far as conducting,when I worked at a car repair shop,we started using silver antseize on battery terminals when we did a tune up. We had a lot of failures and promptly stopped.

I think the mica insulating anti seize would be used on the shielded wire harness that screws on to the spark plugs in aircraft.

John
 
Top threads on a stud should be dry, or have a film of very light oil only. Generally, if a lubricant or anti-seize is used then de-rate the torque applied by 15%.
Use a silicone compound, or paste on battery terminals. 'Dielectric grease' is OK, because it is actually a compound, not a bearing grease.
 
Rocketsled. First answer I have read yet that states in plain english " de-rate torque by 15%" when a lubricant (which I guess is what AS is when it comes down to it) is applied. That means the 55lbs I torqued my cast iron head to with AS is 15% too high. 45-50 would've been better. Too late now though cos the heads are down, and I sure ain't messing with them again!
 
66miles>>>I sure ain't messing with them again>>>

Sure you is! Good practice says you gotta re-torque them a few times after running it. Just make sure they don't go below 45 ft-lbs. And don't go cranking them above either. You'll be fine.

Jack E/NJ
 
I remember one of the never seize products I used stated "like a million tiny ball bearings".
We used a lot of the product for lots of applications, and do not remember any broken studs, or stripped threads due to its use.
The lifers at Kaiser cement did not approve of its use there. Said the cement dust would set up when in contact with Never Seize.
I personally never saw evidence to support the claim.

Bruce

Works good
Lasts long time
 
Bruce,
The folks at plants that processed Calcium Carbonate showed me that RTV silicone worked better than any anti-seize on their nut and bolt fasteners. The nut, and the bolt head would be eaten away, but inside was perfect and was easy to take apart. So, they started coating the bolt heads and nuts with RTV, too, and solved their corrosion problem completely! Not only that, but the RTV worked like a mild threadlocker.
 
Most common anti-seize compounds are not lubricants, as they only prevent galling. Some of the high tech ones will be labeled as a lubricating paste.
 
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