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RoyJ RoyJ is offline
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Default Shade-Tree Metal Hardening

Home heat treating a large lump of mystery metal with some very thin
high carbon drill rod seems like a recipe for odd results.

I don't think I'd bother heat treating the assembly. Instead of using
drill rod, use some straight or tapered dowel pins. These are already
hardened. You mystery metal round bar is likely to be plenty strong to
hold the pins.

www.mcmaster.com page 3275

Tim Wescott wrote:
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.