I should also have mentioned that if I were making something from
stainless that had to be welded together, I'd choose the low-carbon
version of 304 - 304L.  It has less need of the post-weld treatments
that plain 304 needs (fewer carbon crystals to precipitate out). 

   Then again, 304L may be significantly more expensive than plain
304 in your market.

Dale R.

Rusty,

   The main strength difference between 4130 and SS304 (aka 30304)
is that 4130 can be heat-treated, 304 cannot.  Then again, 4130
used in airframe constrution is almost always in "normal" state,
so the UTS values aren't terribly far apart: ~75K psi for 304 and
~100K psi for 4130.

   Yield strength is a different matter.  304 is ~29K psi vs 50K
psi for 304.  If 29K is enough to do the job, then there are a
lot of good reasons to use SS.

   If you are going to do a lot of drilling on 304 (or 316, which
is nearly the same, except slightly better salt corrosion
resistance) get some M42 (cobalt) bits.  304 is hard on tooling.
(Go ahead, ask me how I know ...)

Dale R.
COZY MkIV #1254

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