Changer axle

[J D Sauser]

My understanding is that the order is:
1. Annealed to soften for working/ shaping, (how this stock I have is sold)
2. Heat treated for hardness
3. Tempered to reduce brittleness

Annealed and tempered are similar but for different purposes.

So the piece I have is only annealed. It was easy to cut to length and grind the ends nice and sand and polish etc...

It's not hardened so we'll see what happens.

Thanks for correcting, Ivan.
Makes more sense to me liguistically now. Anealing was a new word to me which I could not relate to French or German.


So Tempered is what I misstook for “annealing” which as you describe is a “warming” process to make “not hardened/heat treated” steels more machinable.
I got some stailess steel pullrods that were “machinable” and indeed I could cut a thread on them manually… slowly, but clean and without losses.

In French, “heat-hardening” is called trempe which means “dipped”…, describing the shock cooling in a heat absorbing liquid. Yet the process of re-softening some is called temperé… “tempered”.

I had mistook “annealing” for tempered.

So, our friend’s changer axle being annealed is now “softer” for tooling purposes when it only needed to be cut to length an slighly beveled on each end for easy introduction in the laterl supports? This while marks cut into the old one by the steel scissors and the aluminum fingers were the reason to replace it.
Was opting annealed “softened” steel the right answer to the problem then?

Thanks… JD

[Ivan Funk]

JD I could be mistaken as I'm still learning more about this metallurgy stuff. The language can misleading yes.

Yes the softened annealed drill rod was intentionally ordered for this project because I have basic tools and not a full machine shop, so it was easy to cut, shape, sand, and polish.
John Hyland's observation about it being better for the axle to wear before the fingers seals the descision to leave it as is and not have it hardened.

Another side point: there are no steel scissors on this Emmons push-pull changer, just aluminum raise and lower fingers.
A fun rebuild.
Thanks for the comments.

[Bobby D. Jones]

To anneal steel that is hardened can be a long process. When I worked in the machine shop as a welder/machinist, Annealing was what we had to do to some parts, So they could be machine worked to repair them. We liked to get those jobs in on Friday afternoon. My job was to take a Rose Bud tip on a torch and heat the piece Red Hot. Then bury it in the lime box about 1 foot deep. Let it set Saturday and Sunday and Monday morning it was still warm. But usually touchable. Then it could be machined.

When tempering steel it is easy to have problems with steel warping even with careful straight down into quench fluid. And heat soaking won't straighten it out.
We usually made the 12" or shorter shafts or pins .020 to .040, oversize with centers in each end. Once the heat treating was done. Set it between centers on a lathe and use a tool post grinder, To finish to exact size required, Then polish if needed. That would be the finish for a changer shaft.

Any soft material, Some aluminums, Brass or Copper will hold abrasive and wear the harder material.

[Ivan Funk]

Thanks Bobby.
Excellent information.