Re: Autolite 3923 washer

[Marco S Hyman <marc@xxxxxxxxx>]

 > My first question in response to your statement: "DO NOT apply Anti-Seize to
 > spark plug threads. You will end up overtorquing the plug and stripping out 
 > the thread in the head" was:
 > 1) <<If one uses a Torque Wrench and tightens the plug to the recommended 
 > torque setting (10 Nm for instance), how can the threads be stripped, regard
 > less of whether or not an anti-seize compound is used?>>

I can answer that one.   The recommended torque setting is specified as
either lubricated or dry.  If specified dry, but you lubricate the device,
the clamping force will be *more* than that specified.   The effect is
the same as over torquing.

Using your example, a 10 Nm reading using lubricated threads applies
much more clamping force than a 10 Nm reading using dry threads due to
the different coefficient of friction.

I do not know if the extra clamping force is enough to ruit threads.
I guess it depends how soft the threads.

// marc

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