I put my hand up to attempt to make a screw type joiner for New Zealand Hiking Poles for a fellow I know. They were cut in half to bring home from NZ to AU when on their honey moon some years ago. These Poles are not cheap some $120 each they have a coin in the top of the handle.
The drawing and plan was for 24tpi but a mate rang to say his boss offered me use of 16tpi tap and die so I jumped at it. I have not cut threads on a lathe for over 40 yrs. I got to dry fit stage today and turned the Pole to suit they are not true round one being very oval indeed.