Is it possible to hot blue chains for rust protection? I surmise there would be parts of a bike chain that are made using hardened steel (e.g. rollers and pins). Would this process affect their temper? Would cold bluing do just as well?

  • 4
    Rust is generally not a problem with chains, insufficient lubrication is.
    – Michael
    Sep 30, 2023 at 6:12
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    If you are after the color, a lot old chains were made in the bluish black color that bluing produces. Velo of Czechia still makes them. I don't know what the actual surface treatment is.
    – ojs
    Oct 1, 2023 at 4:15

1 Answer 1


Excellent question - I know some chains can be bought anodised , so they have a super-thin layer of chemical deposited by electricity. Nickel-plating is done this way.

My first thought is what's already on the chain? If it has any form of chrome or polish then that has to be removed before bluing. Likewise every trace of lubricant or grease would need to be removed else it interferes.

To get a spotless clean you may have to disassemble the chain completely. That alone would put me off.

If you have an old chain handy, it may be worth trying whatever products and techniques you are equipped for. It might be worth trying to cold-blue ~5 links and see how that works.

Given the vertical outer-side plates are the ones most easily seen, you could sand off any existing coating, clean, and then attempt a cold blue. This might leave you with an alternating light-dark pattern.

I look forward to the results of whatever you're able to try.

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    I have been subscribing to restoration channels that deal with chemical stripping. I surmise that one would try to degrease the chain with a supersonic cleaner then proceed to acid stripping. A few neugralizing baths and it would be ready for an attempt in hot bluing. I'll get back on this when I have results. Oct 1, 2023 at 9:21

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