As someone that has bent a lot of music wire springs (I'm a locksmith) I
don't think you need to worry about heat treating the rod. My bending
fixtures were aluminum with dowel pins and the aluminum did just fine.

The trick to bending springs is to figure out how much to bend. If you want
a ninety degree bend you have to bend it further so it stays at 90 when you
relax the spring. Trial and error seems to work here so if you have a bunch
of identical pieces to make, mark your fixture so you know how much to bend.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.


"Tim Wescott" wrote in message
...
I'm going to make a wire-bending fixture for putting fairly small-radius
bends into 1/8" music wire*. I have some 1/8" oil hardening drill rod
and a slightly undersized 1/8" reamer designed for installing dowel pins
in tooling. I also have some 1-1/4" round bar, made of mystery steel but
there's a good chance that it'll harden at least a bit if encouraged.

So I'm planning on putting a couple of pins made out of the drill rod
into the end of a bar, and bending the music wire around the pins. I'm
_assuming_ that if I don't harden the drill rod that it'll bend, although
I'm in a hurry so I'm going to test that assumption by trying to use the
tool.

After I bend up my first attempt at a fixture I'll want to do it up
right. It seems like I should just be able to heat up my whole assembly
to a dull red then chuck the thing into a bucket of water -- does this
sound correct? I have some pottery clay lying around so I'll probably
paint the pins with clay & charcoal in an attempt to protect them from
decarburization. When I fish it out of the bucket should I try tempering
it? If so, how, and how much?

The heat-generating tools I have available are pretty much a propane
torch and an O-A cutting torch. The temperature measurement tools I have
are my own somewhat color blind eyes.

* Music wire is moderately high carbon -- 0.7 to 0.9%, and drawn in a way
that work-hardens it nicely. It's soft enough that you can cut it with
diagonal cutters successfully, but hard enough that you'd better hide the
cutters from their rightful owner when you're done.

--
http://www.wescottdesign.com