I’ve been unwinding springs

[Ali]

I needed to make a guide for a control cable, and there was some nice stainless wire under the bench with a spring in the middle (from an industrial steam iron). Perfect.

I’ve heated it with a torch, then bent and twisted it into the shape I want, no doubt messing up all its properties in the process.

It doesn’t really need to be springy anymore, but it would be annoying if it was brittle and cracked.

Is there anything I should do to heat treat it?

 

[Agroshield]

It doesn’t really need to be springy anymore, but it would be annoying if it was brittle and cracked.

The area of heat treatment you need is annealing or normalising. In effect, heat it up red hot, let it soak a short while (not getting hotter, not burning it, just letting the whole thing achieve the same temperature) and then cool as slowly as is practical.

The classic is to leave in the woodstove overnight as it burns itself out and gently cools down. You can wrap in a welding blanket, push into a bucket of vermiculite, heat up some dry sand in the oven and put into that. As it is a small part, you have to work a bit to make sure it retains its heat, hence pre-heating the sand if used.

 

[frank horton]

seeing ur avatar
I had stainless springs made for the front forks on my Indian...double taper, 6" long....
the guy works in Colchester....very happy with the result.....

 

[RichardM]

If it's only a guide and it hasn't cracked for the piece you're going to put under the washer then try it, the worst case scenario is it cracks and the bit on the cable is free. I used Tig rod when I made some.

 

[outofthefire]

If you've heated it up and let it cool slowly, i'd say it'll be softer already. Some stainless steels work harden, but I doubt you've done enough shaping for that. Unless you know exactly what grade of stainless it is i'd just leave it as is, some grades of ss have quite specific heat treating requirements.

 

[Screwdriver]

Yeah I second that. If you didn't crack it when you straightened it out, it's probably as good as it gets. Otherwise to get the springiness back you'd have to put it through another heat treatment, including hardening/annealing.

There is perhaps a case to be made for normalising, get it hot, let it cool slowly a few times but it really depends how critical the application is. If you're still worried, try a heat treat on a spare length of the same material, see if you can make it better - that is, if you are able to determine how much better or worse it gets!

 

[Agroshield]

...another heat treatment, including hardening/annealing.

It is a little unusual for 'annealing' to follow a forward slash with 'hardening' before it. It would be more usual for 'tempering' to be written in that position.

 

[Ali]

Thanks for all the comments and advice. I need to make a matching pair, so I might do one and leave the other and see if anything happens (by which time I will have forgotten which is which).

 

[Ali]

seeing ur avatar
I had stainless springs made for the front forks on my Indian...double taper, 6" long....
the guy works in Colchester....very happy with the result.....

I'd love to see some pictures

 

[Screwdriver]

It is a little unusual for 'annealing' to follow a forward slash with 'hardening' before it. It would be more usual for 'tempering' to be written in that position.

It is unusual because this is an unusual case where the hardness and temper of the part is irrelevant to its function. This is a simple bracket where it just needs to be the right shape and just happens to be a hardenable material. If the OP were making a blade or cutting tool (or a spring) where a perfect temper were required to draw back the hardness to a precise value then yes, it might be unusual.

In this application where the potential for hardening is an unwanted side effect then annealing is certainly the preferred option. The OP does not need to rapidly cool the item to achieve a specific temper but instead only soften any unwanted hardness/brittleness and allow it to cool slowly.

 

[selectedgrub]

I wanna see a picture of your wife's bike.
You know, that one in your avatar

 

[Ali]

I wanna see a picture of your wife's bike.
You know, that one in your avatar

It’s on the JJ. I want to see more of your bike(s)

 

[RonMig]

I'm all for recycling, I would probably have used some of these as I have a few too many...
https://www.amazon.co.uk/s?k=B0BRB3YTDS