Different kinds of steel, welding etc

[Stu in Tokyo]

OK, I want to make some more curved tool rests for my lathe.

So here comes the very uninformed questions.....

I have a bunch of 1" dia steel rod that I can use for the post part of the tool rest, the part that fits into the banjo on the lathe. For the curved part, the actual "rest" I was wondering if I could use something like the axle from a motorcycle, or a BIG long bolt from a motorcycle?

I have a lot of old bike parts, they GOT to be better, read harder, steel than the mild stuff I buy at the DIY center......... No?

So, if I have this chunk of harder axle steel, I would have to make it softer to work, right? (told you there was a bunch of uninformed questions in this post!)

I think that I would heat the axle up to RED and then shape it, let it cool, drill and tap a hole in one spot for the post to thread into.

I then drill a hole and tap it in the post, put in hard bolt and then

Then I heat the axle rest up again, and let cool, finally I heat it in the wife's oven, to harden it.......... right?

:confused:

What am I missing?

Cheers!

Cheers!

[ThomasPowers]

WRONG

To harden you need to heat it up enough that a magnet will not stick to it (some alloys need even higher temps) This will be glowing red quite a bit over 1000 degF and a kitchen oven will NOT do it.

When it's at that temp it then needs to be quenched in the proper quenchant: Air, Oil. Water, Brine: depending on the correct alloy. Most folks try warm cooking oil first and you will need quite a lot of it, If it doesn't harden enough they reheat it to the glowing temp and try one further down the list.

*After* it hardens you want to *immediatly* temper it in the oven to a lower temp---depending on the alloy it will probably be between 400 and 600 degF

However hardening makes things more brittle. You may want to go with just normalizing: heating up till non-magnetic and letting it cool suspended in still air.

Thomas

[oljoe]

Stu,

I

[Stu in Tokyo]

Helps a lot guys!

I have not had a problem, yet, with the rest, but I've only just started using it, and I've not really done any heavy work with it.

The reason I'm thinking that they may need hardening is that the ones you buy are all "Hardened" this might just by marketing hype, but the commercial curved rests all state that they are hardened. One other thing is that the soft steel straight "T" rest that I made takes a beating, and needs to be filed and sanded smooth all the time, the use of the turning tools on it leave divots, so a hardened rest would not have this problem, I hope.

Thanks again for the great info, I'm learning stuff here every day!

Cheers!