Add a relevant sized nut from the special parts library. (Advance tool palette, Tools menu, scroll down to the Advance steel special part looks like a clevis and insert). Ensure your UCS is properly aligned and copy as required. In the properties assign whatever free remark you wish to appear on drawings.
We have been asking for a threaded rod macro for at least 4 years now (look in ideas and give it a tick)
You could also play around with the Side rail anti sag rod macro in the connection vault under purlins & cold rolled but you may need to put a couple of dummy beams in and remove the joint box afterwards before deleting dummy beams. There will be no intelligence in the connection.
