Fastener torque with different lubricants?

[amuller]

There are tables for tightening specs, but what lubrication do they assume? Lots of automotive torque specs used to be based on "lightly oiled."

I’m pretty sure that if I’m using anti-seize goops based on teflon or moly, the coefficient of friction is going to be lowered and it seems over-tightening is possible.

If gasket sealer is used on the bolts, such as Perfect Seal or the OMC version, what effect does that have?

Thanks for any guidance.

[PugetSoundBoater]

The torque values in the manuals give a RANGE of torque ,for example 45-55 ft lbs. I believe that covers any varience due to the use of anti sieze,or sealant on the threads, IF the torque wasn’t at the top end of the range ,let’s say 53 ft lbs in my example. I don’t think any substance used on the threads would alter the torque too much.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[frankr]

I’d say that if the factory said to use something like their Gasket Sealer, the torque they specify assumes you are using what they said. Now, if you are going to go off on your own and use Teflon or something, you might be getting into uncharted territory. Besides, that stuff might make the fastener subject to loosening because of lack of friction. I don’t know, that’s why I don’t use it unless specified.

[collectorinspector]

This is very good reading and should answer all……

http://www.hexagon.de/rs/engineering%20fundamentals.pdf

One of my fav things aye.

BnC

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