Are Torque specs the same with anti-seize compound on? (1 Viewer)

[e9999]

inquiring minds want to know...
Let's say we have the FSM say to torque -say- the caliper pins at 65 ftlb.
Now say I put anti-seize compound on the thread. Would the 65 figure still hold or IOW, should I still set my torque wrench to 65?
Or is the antiseize compound messing the figures up?
I'm talking in general, not just for this example, of course.
waddaya think? (or better waddaya know ?)
thanks
(and yes, I did put some antiseize on them pins...)
Eric

 

[landtank]

The torque specs don't change just the results.

 

[e9999]

of course. What I meant is whether going by the published specs is still OK or not if one puts compound on. But then these specs may already take that into account...?
E

 

[IdahoDoug]

I've heard conflicting opinions on this as well as read them. I've wondered this for years and asked a lot of experienced engineers and here's the consensus I get.

The torque figure is for a new vehicle being assembled at the factory. All fasteners (bolts, nuts, etc) have a layer of oil on them to prevent corrosion for shipping and storage before they're used. So the torque figure is for lubricated threads. Therefore, you are correct to use anti-sieze and to remain with the published torque figure.

Caveats on anti-sieze I've learned over the years include a specific warning on wheel lugs. Never get anti-sieze on ANY part of the lug/bolt but the threads. If you get it on the cone/seating area of the lug nut for instance, the friction to keep the lug nug tight while the wheel is flexing during use is inadequate and they'll loosen up. In practice, this takes vigilance and wiping down the nuts and the wheel seating surface as the stuff gets everywhere after a few wheel remove/install cycles.

DougM

 

[landtank]

If it is a critical torque the FSM will usually specify what lubricant to use, For example the head bolts require 30 weight engine oil. I've found that anti seize compound actually adds resistance to a cleaned and lubed bolt. The anti seize is a thicker substance. For 99% of the time I wouldn't worry about it.

 

[Scamper]

I would agree completely...if you're that worried about your torque specs, start by buying a very accurate torque wrench ($$$), then get it calibrated yearly. Any difference the antisieze would make is probably much less than your parts, technique and tools will make.

 

[MoJ]

e - you're thinking too hard

 

[tucker74]

Torque specs take into account the tensile stress, rotational stress, and grade of the hardware. You would not want to torque something more because it has greater resistance - it is still putting the same stress on the bolt.

Tucker

 

[RavenTai]

Antisize and other lubricants increase the tension load on the fastener for a given torque because lubricants reduce friction, friction on the threads and under the head of the bolt/nut is part of the resistance to turning when tightening a fastener, the higher the viscosity of the lube and the more area of thread and washer/bolt head bearing surface lubricated the larger the difference, I have read torque needs to be reduced as much as 40% in some cases to get the same tension on the bolt,

Most of the time the difference is ok but Toyota likes to bring some crucial fasteners right up to their yield point, on these fasteners adding lube where none is called for can put it over and the fastener fails (like my rear axle flange studs)

If you do use antisieze try to keep it on the threads only a and compare the specified torque to the standard torque in the front of the FSM, if the specified torque is higher than the standard torque for that diameter fastener be careful

 

[GXO]

[quote author=MoJ link=board=2;threadid=14967;start=msg140998#msg140998 date=1082259015]
e - you're thinking too hard
[/quote]

And when is this a new thing?

 

[e9999]

would that be too hard for my little head or too hard for this forum?

Eric

 

[GXO]

I think you would agree that you analyze any scenario a little more than the average joe. I think this point may cause you to doubt some non-critical or at least statistically insignificant scenarios.

That's all I am saying

 

[Beowulf]

>> I think you would agree that you analyze any scenario a little more than the average joe. <<

Understated. I would say he analyzes all scenarios to the point of absurdity.

-B-

 

[Eduardo96FZJ80]

eric,
how is the A/C doing?

 

[e9999]

not done yet
got the new Orings though...
and a manifold gauge (that won't fit)...
and a recharging hose (that has a busted Oring)...
more to come...

E
hmmm... I wonder if the torque specs are still OK when the bolt is lubed by A/C oil?...

 

[SteveLCetc]

Yep - torque specs discount friction of the threads - so lube 'em up - otherwise they might vibrate loose.

Steve H