gearbox gear tempering

[Gareth J]

I'm not getting far with Google,

I've got a gear, from a simple drive train - meshes with one other gear in a small, oil bathed case.

I've had to get it red hot to pull it off, access was crap and even then was a struggle.

I can get a new gear at about £50 but thought I'd give re-heat treating it a go.

I don't know what sort of steel it would be but nothing too exotic, can't be sure but I doubt any fancy surface treatments.

Any suggestions?

Cheers!

 

[Wendelspanswick]

I'm not getting far with Google,

I've got a gear, from a simple drive train - meshes with one other gear in a small, oil bathed case.

I've had to get it red hot to pull it off, access was crap and even then was a struggle.

I can get a new gear at about £50 but thought I'd give re-heat treating it a go.

I don't know what sort of steel it would be but nothing too exotic, can't be sure but I doubt any fancy surface treatments.

Any suggestions?

Cheers!

If its a carbon steel, by heating and letting it cool, you have Normalised it.
You need to Harden it first, heat to red hot and then quench.
Then Temper it, slightly outside my knowledge base but I would have thought that 290-300 C (cold chisels-springs/screwdrivers) would be a ballpark temper, so dark purple to blue.

You might find its low carbon steel which has been Case Hardened, Tuftrided or Nitrided, if it has been Case Hardened you can use the above method to reharden.

 

[Gareth J]

That's great thanks, particularly a pointer on temper range. It's a newish machine so imagine it will be a suitible carbon steel but is basic so probably nothing ending with "ium" added to it.

 

[Pete.]

If it runs in an oil bath it might not even be hardened. Run a file over it's mating partner to see how hard it is.