any metologist's on the forum?

[Evoman]

If you want something really durable best go for hard coat anodising. I used to have it done on yacht stuff and in addition moving parts were PTFE impregnated. Really hard and very, very slippery. Nothing else we tried lasted as well and the finish was really good. Not a DIY job though, and I recall it used to be about £40 per batch minimum cost 8 years ago. A batch was loads.

[hareng]

Evoman that is hard anodising what Carpdiem describes.
It is very durable and can be impregnated with ptfe, had a few batches done over the years.
A bit hit and miss at the moment doing it myself, harder than 01 or D5 tool steel for sure.