On Wed, 15 Oct 2008 06:44:37 -0400, Pete Keillor
wrote:

On Wed, 15 Oct 2008 05:33:07 GMT, "Harold and Susan Vordos"
wrote:


"Pete Keillor" wrote in message
. ..
snip----.

When you're doing a one-off, you are gauging. By the only thing that
matters, the mating part.

Pete Keillor

Depends on the part, Pete. Fact is, I rarely made mating parts----except in
building tools. Consider that if you're doing defense work, you often make
a single item, with no idea where it goes, or how it fits. That's the
reason for establishing standards, and upholding them, even if they aren't
obvious for given circumstances. If party A orders a part that specifies a
given thread and class fit, you can guarantee the fit by upholding the
specifications.

All too many treat threads with contempt. As long as it works for them
it's good-----but that doesn't always fit in the real world, and it's not
any harder to do it right than it is to do it wrong.

I try to educate in such a way that choosing the proper path becomes
routine. Sizing pitch diameter by dial advancement is one of the things
best not learned. It is not an acceptable procedure.

Harold

Good point, Harold. At least as long as it's not to fit a mop handle,
in which case the appropriate standard looks like 3/4" x 5 TPI,
melted.

I'll go back and re-read your post, then save it. I have no intention
of ever making a part for the gov., but who knows, I might make
something for my own defense. So far, I've not made a thread where I
didn't have the mating thread to compare, but I like learning other
methods anyway. The mating thread might not be accessible as a gage
if it's too big or unwieldy.

Thanks.

Pete Keillor
Came by a couple of 1/2" LH thread nuts, so decided to make shaft
adaptors for motors with 1/2" shafts since all of the available ones
are RH thread. I got to the point of cutting the threads, did my first
pass and checked the scratch against the mating male thread - didn't
quite agree; the original thread was 1/2 - 24, so now I have a funny
spot every 6th crest.
Gerry :-)}
London, Canada