[Vwdiesel] Cracking Sockets

[Val Christian]

> Not tryint to be critical, but where did you hear this, out of curiosity?
> I've found them to be at max fragility with anything over six feet of pipe
> on the breaker bar... heh.
> -James
>
James,

I did a quick search to see if I could find anything on the web I could point
you to.  Didn't find anything with a quick try, so I'll share the anecdotal
data.

Dating back to my youth, I found that sockets on breaker bars tended to
break more when working in extreme cole (at least for this part of the world).
I remember breaking Craftsman sockets routinely near 0F and not at -30F.
Go figure.  Later, comparing notes with the local dairy farmers, who are
hams (we gas on the air on cold nights), I found that they too had problems
with tools (and manure spreaders) breaking at 0 ish temperatures.  Since
I was working near a tribology and metalurgy group, I started asking
questions.  A couple of the old geezers rubbed their chins and said they
would have to look into it.  A engineer straight out of school piped up
with how the chrome vandium in sockets and other tools was most "brittle"
at -10F to +5F, and how it varied with the mixes that different tool
manufacturers used.  Impact sockets were a different mix, and therefore
had different max brittleness points.  The old geezers kind of looked
at the kid, and had the "we'll see" expressions on their faces.

A couple of weeks later, I caught up with the people in that group.  They
had done substantial research, and even tested some material on a large
Instron testing device that they had in the lab.  (They had lots of cool
toys, and were my favored source for liquid nitrogen, if I needed some...)
It turns that the young whipper-snapper was exactly on the money.  And
they had elasticity measurements and curves to show it.  They even
destructed a bunch of tools in the process.

I also know that a grad student did a thesis on the temperature changes in
the structure of various tool steels, and included the cracking sockets
as an example.

If I can come up with any reviewed and published material, I'll let you know.

As a practical matter, when I'm working with tools at the 0F range, I now
heat them up with a pizeo-powered propane torch.  It helps warm my hands,
and I haven't broken any when I do that.  BTW, talking with my aircraft
mechanic on the phone today, he confirmed that he's noticed the same
thing I did, but didn't know of an explaination.

Oh, perhaps if you used your oxy torch, you wouldn't have to use a six foot
pipe so often...  (grin)

Val