Hi MoverZ,

Thank you for making that available. I am not so astute - actually I was "tipped off" by an email from another person. I thought it was important that this information get to this thread. Speilvogel's work is effectively in the public domain as the author/publisher is gone and the only profit to be made now goes to to the used booksellers who I suspect do not send a royalty to the Speilvogel "estate".

Back in 1955 there was only one ASME B31 Code - B31.1. The allowable stress for materials (at temperatures less than creep temperature) was based upon the lesser of 1/4 tensile strength or 5/8 yield strength. Later it became the lesser of 1/4 tensile strength or 2/3 yield strength. B31.3 became the lesser of 1/3 tensile strength or 2/3 yield strength.

Regards, John