> The recent discussions about proper torque on such things as engine mount
> bolts reminds me that over the years I have heard from several normally reliable
> sources that using a torque wrench on locking nuts (either plastic or all metal) is
> not only a waste of time but possibly even a bad idea. 
...
>  In other words, if the torque is really important don't use lock nuts. 
> I am curious what others on the list might have to say about this.

Locknuts are highly overrated. Lockwashers are just as bad or worse.
If a threaded fastener is properly sized for the job, and sufficiently
preloaded or stretched (regardless of the "torque", then it won't vibrate loose.

I highly recommend buying and reading "Nuts Bolts and Fasteners"
by Carrol Smith.
http://www.amazon.com/Fasteners-Plumbing-Handbook-Motorbooks-Workshop/dp/0879384069
It is written by a race car builder who isn't afraid to name names and
tell it like it is. There's good engineering explanations, and much about
the proper way to use a bolt or nut. Keep in mind that race car builders
use most of the same construction techniques as airplane builders,
but stress the components much closer to the limits. Race cars have
much more vibration and more moving parts and attract some of the
best engineering talent. There is much to learn from those guys.

-bob

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