Dry ice is what, -40C? We get those kind of winters up here so your
pins would fall out <G>. Better to use liquid nitrogen.
Heating the work with a pinpoint flame is
pretty easy to do, and you get much larger diameter change for a
given temperature change when you have a ring, rather than a pin.
IOW, heating the hole works better than trying to cool the pin.
And the lower thermal mass of the pin means you'd better be darned fast.

Robert

Josh Koffman wrote:
>
> This is an ok idea, but I believe part of the reason heating the brass
> works so well is because it will expand more than the steel will.
> Cooling steel might not make it contract enough to get a tight fit. I'm
> not an engineer though, so you might want to check out the physical
> properties of the metals.
>
> Josh
> --
> A common mistake that people make when trying to design something
> completely foolproof is to underestimate the ingenuity of complete
> fools.
>         -Douglas Adams
>
> Mike Hord wrote:
> > Now that's a good idea.  We routinely use dry ice in our lab, and I believe
> > it would be far easier to use the dry ice to reduce the pin than a heat gun
> > to expand the work.

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