Generally, for standard threads, a simple thread callout in the notes or directly on the view is sufficient. For example, “M6 × 1.0 – 6H” for metric or “¼-20 UNC – 2B” for imperial. You usually don’t need a full section unless it’s critical for fit or assembly, as standard threads are universally understood.

For non-standard or custom threads, I’d recommend a full detail view or section, showing major/minor diameters, pitch, and thread form. This ensures the machinist or supplier clearly understands what’s required. Sometimes you can reference a company standard or an ISO/ASME spec if it’s internal.