So, got something from my spring manufacturer.

Ultimate conical spring(Rev 5.1)
Material: Beryllium Copper Titanium C17550 60% IACS

That last one actually comes from one of the R&D centers of the spring manufacturer.
It’s a prototype alloy, from what I understand, having slightly less beryllium and a touch of titanium.
Much more expensive than BeCu C17530, and still quite a lot more than C17500.
But its conductivity crushes C17530 by a long shot while having similar mechanical properties.

If we can actually get this in our springs, that would make them the absolute best.
However, the price would easily double, or even triple, according to the manufacturer.
Will stay in the R&D phase for now. :slight_smile: