If your measuring 8 threads in a 1/2" the spindle size would be 3/4 x !6 which
is a very common size in smaller lathes.
If it is indeed 3/4 x 8 you would only see 4 threads in a 1/2". Kind of
unlikely but I guess anything is possible.
Spindle threads are measured by the amount of threads in 1" of spindle length.
If it is 3/4 x 16 both chucks you mentioned are available about anywhere chucks
are sold.

I'm new to this news group and turning. My problem is my bottom of the line
lathe. It has no morse taper in the head stock and the threads are 3/4" X 8
or 10 TPI (only have a half inch of threads to measure).


Bob, Naugatuck Ct.
http://www.outofcontrol-woodturning.com