On Sun, 6 Jul 2008 09:13:29 -0700 (PDT), woodworker88
wrote:

Sounds good to me. It just so happens that there is a 8" 6-jaw chuck
on the Colchester 15" lathe at work. Our tooling cabinet has a good
selection of really large taps, so maybe there is a 1 1/4"-20. I
believe the spec for the thread is more complicated than that (I
always see it called out as some decimal diameter) but perhaps
something will work. I can compare the thread to a new Hardinge
collet.

Hardinge specs the thread as 1.238-20 in the "Total Workholding"
catalog. You may find the relevant section here...
http://www.hardinge.com/?pageId=141

--
Ned Simmons