Stainless steel welding rods

   #1  

WilliamTO-35

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A couple of years ago, as a beginner arc welder, I tried several types of coated rods on mild steel , using my AC/DC arc welder. I found that, using a stainless steel rod ( ID number now unknown) , I was able to lay down some very nice looking beads . But, they turned out to be only about one half the strength of steel rods, such as 7014 and 7018 . I compared strength by doing butt welds on long pieces, and breaking them by hand . Are stainless rods typically that weak ? Thanks.
 
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Raspy

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Don't know if they are weaker overall, but a 316 SS rod will weld high carbon steel without cracking, such as with farming discs.

It's been one of my go-to rods for years. I don't remember a failure where the rod material was too weak.
 
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Spanner

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Don't know if they are weaker overall, but a 316 SS rod will weld high carbon steel without cracking, such as with farming discs.

It's been one of my go-to rods for years. I don't remember a failure where the rod material was too weak.

:checkmark:
 
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LD1

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U sure it was a stainless rod?

Alot of exotic "maintenance" type rods ate a stainless based. Harris super-missle is one that come to mind.
 
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yomax4

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Stainless rods are pretty tough. Super Missile rod mentioned above has a 120K tensile strength. They could easily be more brittle though. The higher the tensile the lower the ductility. for instance 308 stainless filler metal has about 85K tensile. Still pretty ductile at that tensile so I can't imagine breaking the weld unless it was porous and cold. Try it again, you will likely see different results. Stainless is a favorite stick rod.. very nice to use.
 
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Raspy

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U sure it was a stainless rod?

Alot of exotic "maintenance" type rods ate a stainless based. Harris super-missle is one that come to mind.

The rods I've used and keep is stock say 316 and 309 on them. Those are the only stainless rods I buy and they have welded things others wouldn't. I think it's the high nickel that makes them work on high carbon. Excellent rods.
 
   #7  

swines

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Stainless rods are pretty tough. Super Missile rod mentioned above has a 120K tensile strength. They could easily be more brittle though. The higher the tensile the lower the ductility. for instance 308 stainless filler metal has about 85K tensile. Still pretty ductile at that tensile so I can't imagine breaking the weld unless it was porous and cold. Try it again, you will likely see different results. Stainless is a favorite stick rod.. very nice to use.

The rods I've used and keep is stock say 316 and 309 on them. Those are the only stainless rods I buy and they have welded things others wouldn't. I think it's the high nickel that makes them work on high carbon. Excellent rods.


Super Missile Weld (SMW) has more nickel than any of the stainless rods. I've read many comments about SMW saying "It's the same as 312 stainless" - it's not.

Here are the chromium and nickel contents of some common stainless rods and SMW from a publication by Harris.

308
Cr = 19.5% -22%
Ni = 9.0% - 11.0%

309
Cr = 23% -25%
Ni = 12% - 14%

312
Cr = 28% -32%
Ni = 8.0% - 10.5%

316
Cr = 18% -20%
Ni = 11% - 14%

SMW
Cr = 35%
Ni = 25%

As you can see, SMW has more chromium and nickel than any of the common stainless filler rods. I have 308, 309, 312, 316 and SMW TIG filler rods. By far, the SMW works better for carbon steel to stainless steel welding. For pure stainless, I try to match the filler to the stainless as there will be very slight color differences in the finished weld compared to the surrounding metal. If color is not a consideration, the general rule is that a higher number alloy is okay to use with a lower number stainless alloy. As an example, 308 rod on 304 stainless.
 
 
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