On Tue, 12 Feb 2008 07:37:32 -0800 (PST), John Martin
wrote:



That said, I've never heard of a 7 TPI lead screw, and can't imagine
why you'd want one.

John Martin


Does it count that my BCA jig borer (actually an Excel Model "0" ) has got
14tpi leadscrews on both axes of the table?


In this case, someone installed 7/16" Whitworth screws, either when it was
made in the middle of WWII, or at some later date. They'll get replaced with
10 or 20tpi ACME ones when I rebuild it.

Mark Rand
RTFM