"The Hurdy Gurdy Man" wrote in message
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In rec.crafts.metalworking Ed Huntress wrote:

After smashing the hell out of them with a big hammer on an anvil, I was
convinced that there is nothing at all brittle about those joints, even
the ones TIG welded with 4130 rod. I could pound them flat, fold them
over, and so on, without a crack at the weld. The pieces did eventually
crack in various places, but that was after they were tortured beyond
belief.

Hmm... well, maybe Finch is actually on to something for a change. Thanks
a bunch for sharing your experience with it! I spoke with my welding
instructor today, and he apparently spent a lot of time training on
chromoly back in the Navy... they didn't do any stress relieving on the
coupons either before testing them. In tensile tests, the correctly
welded parts never failed at the joint or in the heat affected zone
either, which makes me think that quite possibly Finch is completely
correct in that the torch heating stress relief rigamaroll isn't effective
enough nor required enough to matter. Probably still a safe bit of
insurance to do it, but it does make me think that it's not as critical as
many of the sources I have read have made it out to be. Thanks again!


Without digging out my research, I can say that most reputable sources I've
read say that no pre-heat or "stress relieving" is necessary with 4130
tubing in wall thickness of 0.80 in. or less -- one said 0.065 in.
Somewhere, the EAA says NOT to do it. Somewhere else, their various
independent authors say to do it.

But those are mostly older references. The newer ones tend to say not to try
to stress-relieve 4130 with a torch.

Ed Huntress