Welding 4130 chromoly with a stainless steel Tig welding rod
Can I weld 4130 with a stainless steel welding rod? That’s a frequently asked welding question seen on all sorts of internet forums for auto racing, homemade planes, go karts, baja racing, bike builders, drag racing, and other motorsports forums.
It’s obvious that a lot of people are tig welding 4130 using stainless steel rods like 308, but that doesn’t mean it’s better than the old E70s2 mild steel tig rod. Why would you want to use a more expensive welding rod if it hasn’t been proven to be better?
I can get an E70S2 tig welding rod for about $3 a pound. But 308 stainless steel rod costs about $10 a pound. Other stainless steel rods that some people use to weld chromoly, like 309, 310, or 312, cost even more, like upwards of $20 a pound.
I’m all for paying a little more when something works better, but I need proof and the only proof I’ve found is people saying they like the way stainless steel rods are welded. Welding sure looks good when you use stainless steel rods…all shiny with different colors…and you know what that means?
Any!
The problem with using a stainless filler rod to weld chrome steel is that different welders will get different results. Not the appearance of the surface, but the microstructure. Each welder will obtain a different degree of dilution and therefore the microstructure of the weld made with stainless filler metal can be unpredictable.
Predictability is very important when it comes to things like planes and racing cars. As old Hank said to his son Bobby in King of the Hill… “Bobby, women love predictability!” Using the E70S2 filler rod results in a more predictable weld microstructure that is less reliant on the welder for good results.
Predictability in both welding and women is underrated.
