On Mon, 05 Nov 2007 19:58:59 -0600, Richard J Kinch
wrote:

Ed Huntress writes:

Are you taking this from the ANSI/ASME B1.20.7-1991 (R2003) spec,
Richard?

Yes, via MH.

I don't have access to that stuff these days, unfortunately,
but is it something in there that leads you to say it can't be tapped
or die-cut?

Yes, as my earlier post stated, the features of the *nipple* (male
component) and the *coupling* (female coupling) include not just the
thread, but also a pilot, a relief, and a different lead-in thread angle.
That's not to say you can't tap or die-cut the .75-11.5 thread itself, but
that thread is only one feature of these couplings. The other features
require (as standard states) cutting, rolling, or thin-wall forming, not
tapping or die-cutting. So a tap or die alone will not do it.

That's true. Your earlier post was not wrong, sorry 'bout that. The
tap and die I saw were the right thread, but they don't make those
other features. Those features, if they're really necessary for the
application, would have to be made on the lathe that also makes the
male "blank" of 1.0455 to 1.0625 OD, ditto for the appropriate blank
for the coupling.