Hi Michael ,
I think Cosmetic threads will be very useful in this case. This is Available Under Insert > Annotations > Cosmetic Thread . And also Other thing once you use this see whether the option under Tools > Option > Document Properties > Detailing > Shaded Cosmetic Threads Is Checked inorder to view those Threads.
Thanks & Regards ,
If you want actual threads (or anything else for that matter) to show on drawing - you will, of course, have to model the feature.
Threads are trivially easy to model - but are computationally expensive (will create larger files and slow down SolidWorks).