Welding Stainless Steel – How to Weld 303 Free Machining Stainless


Welding stainless steel is gravy. Well, at least most of the time that is.

Here is a story about a certain kind of stainless that is not so easy to weld.

“Hey John,  you can handle tig welding 303 stainless steel, right?”

That’s the question that the machine shop owner just asked you right after notifying you that your welding shop won the contract that pays 18,000 dollars for welding 4000 spindles made from 303 stainless.

And by the way, the parts are already machined and on a truck on its way to your welding shop.

You ignore the 303 stainless steel comment because you know stainless steel is a piece of cake to weld…

Your welders are certified. They are craftsmen. They take pride in their work. There is no problem

The day the parts arrive on a pallet, your welders are drooling over all the gravy work they are about to do. Your welders love stainless steel and the quality they produce is nothing short of artwork.

“This Stainless Steel welds like crap! I think I may have some bad argon!” says your top dog welder as he lifts his hood after welding the first of the 4000 axles.

“Its undercutting, and it just welds funky. Something is definitely wrong.”

You swallow hard. Your stomach sinks.

You are committed to getting the job done. You need the money badly, and you want to impress the machine shop owner so she will keep sending you work.

So here is what you do…

Follow these tips for welding 303 stainless and things wont be so bad.

  1. Use 308L filler rod
  2. use just enough amperage to make the weld
  3. add a little more filler metal than you would on 304 stainless
  4. hold a tight arc to prevent undercut
  5. taper the amperage slowly if you are tig welding to prevent crater cracking


Source by Jody Collier

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