Does Rhino have a thread tool like Fusion 360 or something similar to model threads?
I haven’t used BoltGen, but perhaps you can use it and finally cut off the parts you don’t need? (if bolts are not what you intend to draw)
As Rolf stated bolt gen is a great free tool at food for rhino. I have been using it for quite awhile and I think it is wonderful.
Hope this helps … Danny
I tend to go to McMaster-Carr and find the bolt size and thread type I want and download the STP or Solidworks file and import it.
If you make something that gets 3D printed then you’re threads might just need to be run with a tap / die of the correct size and you can then use standard hardware.