I am machining some replacement axels for Tom Bee trucks. I am looking for does and don’ts for turning the 52100 bearing steel.
What temperature/color do you draw it after hardening it?
Thanks
Tim
Machining 52100 Steel for Axels
Moderator: Harold_V
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Machining 52100 Steel for Axels
He who dies with the most unfinished projects: Should of put more time into their hobby.
Re: Machining 52100 Steel for Axels
I'm curious why you've made that material your choice. It's far beyond anything you might need unless a part of the axle becomes a bearing. Still, you have other choices, including Stressproof, which can also be hardened. With induction heating you can harden specific areas, leaving the balance of the material in an annealed state, so it has greater ductility. That is common practice for items such as spindles for lathes.
For pretty much any material, the draw temperature would depend on your intended use. For 52100, this might help:
Assuming a minimum draw @ 100° C, you'd retain the approximately 63Rc hardness.
Assuming a draw @ 200° C, you'd drop hardness to approximately 61Rc.
On a French curve, by drawing @ 650° C, you would expect a hardness of approximately 30Rc.
H
For pretty much any material, the draw temperature would depend on your intended use. For 52100, this might help:
Assuming a minimum draw @ 100° C, you'd retain the approximately 63Rc hardness.
Assuming a draw @ 200° C, you'd drop hardness to approximately 61Rc.
On a French curve, by drawing @ 650° C, you would expect a hardness of approximately 30Rc.
H
Wise people talk because they have something to say. Fools talk because they have to say something.
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Re: Machining 52100 Steel for Axels
The ends will ride on needle bearings. This is the material that Tom Bee uses.
Tim
Tim
He who dies with the most unfinished projects: Should of put more time into their hobby.
- Bill Shields
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Re: Machining 52100 Steel for Axels
Hope you were able to grind the surfaces to size..not so much for size but finish.
Too many things going on to bother listing them.
Re: Machining 52100 Steel for Axels
Yeah, what Bill said. Unless you can provide an inert atmosphere, or can protect the surface by other means (enclosing in stainless wrap is one way) the ends will be oxidized. If heating for heat treat is prolonged and in the wrong atmosphere, you can also experience decarburization, resulting in the surface being unable to be hardened. You should explore all of these situations before jumping in, as you may experience failure.
Decarburization can be addressed by a neutral or carburizing atmosphere, or by leaving excess material, which would be removed after heat treat by grinding.
It would not be in your best interest to heat treat without grinding afterwards. Even under ideal conditions, the critical diameters may undergo changes that you can't correct. How the parts are quenched is critical, as the wrong quench method can easily yield bananas.
I'm not trying to discourage you. Just make sure you understand all the ramifications of heat treating.
H
Decarburization can be addressed by a neutral or carburizing atmosphere, or by leaving excess material, which would be removed after heat treat by grinding.
It would not be in your best interest to heat treat without grinding afterwards. Even under ideal conditions, the critical diameters may undergo changes that you can't correct. How the parts are quenched is critical, as the wrong quench method can easily yield bananas.
I'm not trying to discourage you. Just make sure you understand all the ramifications of heat treating.
H
Wise people talk because they have something to say. Fools talk because they have to say something.
Re: Machining 52100 Steel for Axels
If the axle diameter allows I would suggest using a hardened & ground sleeve on an unhardened axle for your needle bearing to run on. They can be Loctited on and replaced when worn, keeping the axle straight won't be an issue.
Denny
Denny
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- Gary Armitstead
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Re: Machining 52100 Steel for Axels
Sounds like "over-kill" for trucks to me. I have multiple pieces of rolling stock in 1-1/2 inch scale. Many varieties of brands of trucks. I've had half-bearing blocks on many trucks with over forty years of use on them. The cold rolled steel axles still look as new as the day I turned them over forty years ago!
Gary Armitstead
Burbank, CA
Member LALS since 1980
Member Goleta Valley Railroad Club 1980-1993
Burbank, CA
Member LALS since 1980
Member Goleta Valley Railroad Club 1980-1993