Summary

Very small design, very fast to print, so your settings to print turn around time is very short, this way it goes fast to fix settings for best possible performance of your FDM or Resin printer
The 100% size screw and nut, is possible to print in 0.2mm layer,
0.4 nozzle and they fit togeter a little bit tight.
then try with 0.1mm layer height, and see how much better it goes.

if you are up for the challenge, see how small you can print them
and still screw them together, but it is NOT an easy task :-)
What you get out of this, is perfect settings for your printer
now you can print better looking parts that fits better together,
post a make of the smallest you can make,
and reveal your settings and nozzle diameter and layer height.
(thanks to TB for design and challenge idea.)