Tools & Fabrication - what wire for stainless to mild steel

Hey guys, im mig welding stainless to mild steel. what wire should i be using for this?
thanks

from what i found, it says i just use stainless wire. i was using ER308L and the welds were not very good

Try a steel wire. For your average welds its not that crucial.

with tig you use a 309 wire...dunno if you can get that for mig or not...

Maybe you could describe the workpiece and its intended
(ab)use.

Sometimes dissimilar metals are better off brazed.

What does "not good" mean, for the welds? Ugly, brittle,
??? Are you sure this is not settings or shield gas, more
than metal related?

You still use the same steel wire. It mostly depends on your gas. 75/25 gas mixture will weld it no problem.

Stainless likes the tri mix :nod:

oh okay, ill just use the wire that i weld steel with. btw, im welding mild steel flanges to stainless headers

On this application, running the mild steel wire will be perfectly fine. Doesn't mean its the "best" option but it is just header flanges ;)

309L. That is what it is designed for.

im welding what a flex coupling into my crossover, it says its stainless, and my crossover is mild, anything i should be weary of?? just have standard steel wire .035. using a millermatic 211 with autoset, which is amazing my the way, lol

You can weld stainless with regular steel wire with no sweat. Its not the correct way but will it hold and function in most applications? Absolutely.

Inconel when in doubt.

309L is the correct rod. Your "steel mig wire" I'm guessing is ER70S-6...which does not contain the proper amounts of nickel among other elements to make for a sound weld. It will be brittle and most likely crack after multiple heat cycles, IF you get good fusion to both parts. There's a good chance it will never give you any trouble, but you asked what was right, and 309L is right....i have a 10# box of it I need to burn now that you mention it....

....and a tri-mix gas would help

I've welded setups like that with steel wire. No failures in 8 years, even welded a few turbo setups like that.

309L. That is what it is designed for.

x2 309L

Stainless, or a wooden rod...:pimp:

309 is the proper wire.... its my usual all metal wire. Its harder to find then 308..... that said, I have welded mild steel perfectly fine for non critical apps with common 308 wire.... mostly because it got loaded on accident and I didn't know until the reel went empty.

ER70S6, 309 stainless MIG wire will be hard to find

309L


Buy online and it's not too hard to find.....

if its not structural or prone to warping from heat I would say it doesnt matter. Ive welded stainless bungs to stainless pipe using mild steel mig wire and standard 80/20 argon mig gas without any issues. Ive also welded stainless to stainless with stainless wire using mig gas and also havent had issues, but none of this was structural or on exhaust sections to large that heat/cool cycles would cause issues. my 2 cents

I'm gonna jump on the band wagon and say 309L as well. Even though I am currently welding 304 to mild using 308... but whatever.