Stainless steel spring weld question

Braze or silver solder it.

Ernie, I like welding as a hobby and was told never to weld springs. I know you teach welding, so I respect your suggestion below. Can you offer any insight why one would braze or silver solder? Is it because the metals are dissimilar? Won't it fatigue and break due to different stresses?

--George

No problem, we have done it many times. We usually resistance weld them but have also Tig, Electron beam, and Laser welded too. Be sure to only use the dead portion of the spring coil.

As long as it doesn't flex it won't break? Sorta what I was thinking anyway.... Kent

If you silver solder the spring you are less likely to get a fracture than if you weld it.

Yes if you flex the joint enough you will eventually fracture the solder joint, but you haven't listed much in the way of detail.

Is that due to the heat or the composition of the filler material ???

I was just asking in general. I suppose it would depend on whether you were on a part of the spring that is actively flexing or not.

You are more likely to get grain growth in the structure of the steel by welding it due to the higher heat.

Soldering uses less heat and shouldn't allow the spring to weaken. It will remove the temper in the immediate area unless you quench and re-temper after soldering.

Yes.

I have welded two or three carbon steel springs. I certainly wouldn't do this if there was a chance of somone getting hurt if it failed but... I TIG welded the spring. Butt weld using 312 stainless filler. I then cleaned and heated the area at and near the weld until I got a purple/blue colour (spring temper). This will help the HAZ without harming the region further away.

This was over a year ago and both fixes are still functioning well.

Ted

Ernie While it's true that soldering shouldn't weaken the spring if a low temp solder like 60/40 is used, quenching and tempering are not going to help. That's because 300 series stainless steel gets its hardness by work hardening (i.e. drawing wire) and not by heat treatment like high carbon steels do. Tom

I have never seen stainless steel springs made from 300 series stainless steel. I have seen them made from 410 SS.

When it comes to coil springs, 302 stainless steel is probably the most common spring material, maybe even more so than music wire. These are some vendors we purchase stock 302 SS springs from.

Guys, Add this to the list for the low volume buyer:

I did a prototype or two and submitted them for evaluation.

Ernie, The 400 series are martensitic and so the rules for welding carbon steel springs apply: DON'T

Thanks Tomcas and Ernie!