Dear Mariog,

Yes in c2quick.pdf file, the default Slp = P*ID/(OD^2-ID^2); code exact equation, Caesar default. We can find also in Popov's book this Eq. I will try to recalculate.

But my point is: "Actually if we purchase OD, ID, T bar pipe (as per ASME B36.10M), regarding to mill tolerance, does it mean that it is possible that they will deliver us with size OD', ID', T pipe? someone experience in fabrication/manufacturing please explain"

If it is possible we have OD', ID', T, from manufacturer does Caesar anticipate it?