Maybe you can use an existing nut and modify it to your needs.

Try: http://www.greenbaymfgco.com/catalog.php

Also, I don''t know about Sheldon lathes, but I see new crossfeed nuts
for Atlas lathes on Ebay from time to time.

Pete Stanaitis
----------------

Gerry wrote:
Sometime in the future I will need to make a new crossfeed nut for my
old Sheldon lathe. Didn't seem like a big deal until I realized that
duplex taps are not available in 1/2"X8tpi Acme.Y'all have any
suggestions? I really don't want to have to grind a tool to cut Acme
threads that small. I think I'd farm the job of making the nut out
instead if that was the only way. I could convert to 1/2"X10tpi but
I'd have to make a new dial graduated to suit as well