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From: Andy Little (andy_at_[hidden])
Date: 2006-08-23 14:26:44

"Greer, Joe" <jgreer_at_[hidden]> wrote in message
>> FWIW If I use a hefty spanner to undo a rusty bolt, then the bolt
> heats up
>> as I
>> unscrew it. I guess the heat energy gained by the bolt is directly
>> equivalent to
>> the torque I had to apply to undo it. OTOH therefore one would think
>> that
>> applying heat to a rusty bolt should make it unscrew itself but
>> unfortunately
>> for some reason I have never been able to get that to work ! ;-)
>> regards
>> Andy Little
> As a former Ironworker, I can tell you that if you apply enough heat,
> the rust will often pop right off. If that doesn't work, then you apply
> even more and... what bolt was that you were talking about...

OK. I'll make sure Not to invite you round next time I need to get the sump plug
off my motor ;-)

> Just had to chime in from the peanut gallery.
> Also, make sure that you are solving problems that are really likely to
> occur. It is nice to be as absolutely type safe as possible, but often
> that gets in the way of getting real work done as well. Just a thought.

I think the following quote (lifted from Quickbook) fits quite aptly here:

"Why program by hand in five days what you can spend five years of your life

-- Terrence Parr, author ANTLR/PCCTS

The serious point was that there is a relation between torque and energy, but
they are distinct.
 and actually the relation is slightly more complicated than I stated, but I
think that for a bolt of N turns
and assuming a constant torque, the heat dissipated (in Joules) ==
applied_torque (in N.m) * N / (2 * pi).

Andy Little

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