These connectors are for use on 5mm output shaft steppers and 3/8ACME threaded rod.

1) Print
2) Insert 5mm nuts into nut capture slots on bottom of the part. Start M5 x 10 SHCS into nuts
3) Clean up ACME threads if necessary- I used a short section of ACME rod scrap chucked into a drill
4) Assemble.
5) tighten M5x10 SHCSs to fasten to stepper. If necessary a couple drops of epoxy could be used to lock ACME rods into place, I've been running my printer with no adhesive to lock the connectors to the ACME rod. Friction alone seems to be enough.