[Shop-talk] Minimum wall thickness on tubing

[Chris Kantarjiev]

> I need to make straight-cut outside threads on some B= " steel tubing.
> I can buy the tubing in various wall thicknesses.  What would be the
> minimum wall thickness needed to produce good threads that won't weaken
> the tubing using your basic tap and die set?

"It depends".

Let's assume you're talking about ANSI 60 degree thread form, since that's what
you'll find in a basic tap and die set. The thread depth is 0.650/tpi,
so if the wall is exactly that thick, you'll have nothing left when 
you've cut the thread. 

But that's a flat top thread. Your dies may cut a sharp V thread, where
the depth is 0.866/tpi. 

So those are the baseline required thicknesses - can't go thinner than
that. Now you have to decide how thick you need the root of the
thread to be, given the material and application.