sk wrote:

I machined a replacement insert from O2 round stock, currently at Rc
20, will this last a few years without hardening?

Probably not.
The material should be shatter proof and corrosion resistant. Federal Mogul
has valve seats (and should have stock material to make your own).
If you can't get that, cast iron (not the softest one) should be a fix. If
it has nickel/chrome in it, the better.


Nick
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