Oh boy, I’m looking for trapezoidal (like ACME thread) screws and nuts in left hand form. The rods are already expensive, but nuts feel like a total ripoff. A hex nut for Tr20x2 being 30mm long and 30mm in “diameter” costs me 22 bucks! O_o Just a single one, made of regular steel. A meter of rod is 21€. The more common Tr20x4 hex nut is just 7€ and the rod 17€, but 4mm pitch is a bit much for a leadscrew for semi-precision work I reckon.

Well, maybe I just use metric threads. I will sleep on this.