You need to heat it to about 1500F to 1600F, oil quench, temper at 900F
to 1100F depending on exactly where you are trying to get to. Neither
one of those temp ranges is easy to get to with just a torch or a
kitchen oven.

des bromilow wrote:

G'Day,

We've got a piece of 1/4" spring steel rod (as hard as piano wire) -
typical grade spring steel (1080) which we need to make a tightly wound
shape with.

The local spring guy told us to form the tight curves (around a 3/8"
bolt) by annealing the wire to dull red and winding around the form, but
obviously this then leaves the rod in an annealed state.

How to we then harden and temper the rod back to a spring?

The shape is best visualised as the metal frame of a slingshot (it's
actually part of a motorcycle seat) so it won't make full contact on a
flat surface.

If someone with some experience in this type of work can tell us the
proper way to harden and temper this we'd appreciate it. We have
oxy-acetylene, and propane torches available, and our previous
experience with this spring steel grade has been to quench in oil.
If you can tell us the colours to heat to, or temperatures it'd be great
- similarly if you have any tempering methods to acomodate the irregualr
shape (is a domestic overn OK to use?)

Thanks,
Des

remove the german anti-spam device off my email address to reply