Hardox for starter ring gear?

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turbobaldur
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Hardox for starter ring gear?

Post by turbobaldur » Sat Jul 11, 2015 8:00 pm

I'm considering getting a starter ring gear machined on a water jet machine for a custom application, I'm wondering if hardox is a good material for it.

BCjohnny
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Re: Hardox for starter ring gear?

Post by BCjohnny » Sun Jul 12, 2015 5:49 am

Not necessary. Any flame hardening medium carbon steel, EN8 (1045) for example, will get it done. Try to just harden the teeth section, ~45-50 HRC. Don't anneal it sweating it on.

Rub a file over an OE ring gear some time, you'll see it's not that hard. There is a reason.

[OE gears are usually rolled circular from rectangular bar & welded prior to machining]
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turbobaldur
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Re: Hardox for starter ring gear?

Post by turbobaldur » Thu Jul 16, 2015 7:27 pm

In that case the question becomes if A284 is a suitable material. I don't have a great selection of alloys locally available. There's hardox or domex as used for hard wearing surfaces in mining equipment and then there's mild steel, A284 or E360B.
The question really is, is there a reason not to use a hard wearing steel for this?

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Re: Hardox for starter ring gear?

Post by BCjohnny » Fri Jul 17, 2015 4:01 am

turbobaldur wrote:In that case the question becomes if A284 is a suitable material. I don't have a great selection of alloys locally available. There's hardox or domex as used for hard wearing surfaces in mining equipment and then there's mild steel, A284 or E360B.
The question really is, is there a reason not to use a hard wearing steel for this?
Without checking the specs, haven't a clue. 'Brittleness' of the relatively small teeth will become an issue with some materials, for obvious reasons. Ring gears are much softer/ductile than starter pinions because it's the best compromise. Absolute 'hardness' of the ring gear per se is not the issue.

EN8 etc, or a selection of the 104x &105x medium tensile hardenable steels should be suitable (caveat; obviously up to you to confirm for yourself prior to using), they shouldn't be exactly expensive or hard to come by, even accepting your location. Using materials for specific tasks just because you have access to them can be a bit of a lottery .......
"If an honest man is wrong, after demonstrating that he is wrong, he either stops being wrong or he stops being honest." Anon

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