[Shop-talk] Identifying taper and threading attachments on a

[David C.]

Not necessarily; chasing or "picking up" an existing thread on a lathe 
with a threading dial is (or at least was) a pretty straightforward task 
for the average machinist.  You just get the cutting tool close to the 
threaded part, close the half nuts at the appropriate mark on the 
threading dial, stop the lathe, then very carefully use the cross and 
compound to seat the threading tool in the thread and proceed as normal.

Dave

Arvid Jedlicka wrote:
> When they removed the pipe from the chuck after threading all bets were
> off as to synchronizing the existing threads with the cutter when they
> put it back in the chuck.  Easier to just start over again.