I'm trying to sort out my materials order for an exhaust system based on your
Russian square tube design, and finding some components difficult to locate
or impractical to purchase.
For the exhaust flange, I cannot find 3/8" 321, sheet or bar stock in a cost
effective size. I can find 1/4" 321 plate, but would have to purchase an
entire 96"x260" piece.
1. I was wondering if using a burns 304 stainless turbo flange would be a
suitable substitution? If not do you have any suggestions?
2. in order to reduce some fabrication time, would 316 2"x2" .065 wall sq.
tube (or .062 304 )be satisfactory to go from flange to beginning of
spiral around the can?
Thanks for your time.
C. Smith

Most people use mild steel for the flange as it is thick enough not to be bothered by
the heat. You could also use the four bolt pattern and then use 304 SS 1/4 inch thick
flange.

Same goes for the square tube .065 304 would be fine. There is always a trade
off. The lower the temp steel the thicker the material. .065" 321 is overkill.
The muffler can also be .065 304. In fact if you want to make the muffler .049 304 SS you
can always weld a doubler .065 patch where the exhaust gases impinge on the pan
opposite the ports.

Welding SS to mild steel is no problem.

Paul Lamar