On Mon, 13 Oct 2003 20:22:56 -0400, Ned Simmons wrote:
Oh, come on, Ed. What's so different about pipe threads
that they don't "exploit the strength of the material"? The
sharp thread form likely causes some stress concentrations,
but other than that, I don't see much difference.

They're *tapered*. That means you don't have full depth threads
engaging full depth threads at any point in the joint. Machinery's
Handbook says that only NPS threads should be used for axial
loading.

Gary