Lead screws are expensive, and hard to come by in all but specialist tool shops. That is why we all use the less than ideal threaded rods in our designs.

Looking for a machined lead screw, I saw a 400mm long 8mm SDS drill bit hanging behind the counter. Got me thinking...

The attached lead screw nut is scripted in Openscad to fit the Alpen F4 forte 8mm L450/400mm SDS-plus dril bit. I cut off the cutting tip, and threaded on the nuts. Looks very promising...

UPDATE:
Installed it on my reprap Morgan machine, and it works great!


Added the scad file for your own experiments.