ASME - American Society of Mechanical Engineers
No. of pages: 28
ASME B16.4 - Gray Iron Threaded Fittings: (Classes 125 and 250)
This Standard for gray iron threaded fittings, Classes 125 and 250 covers: (a) pressure-temperature ratings (
size and method of designating openings of reducing fittings © marking (d) material (e) dimensions and tolerances (f) threading, and (g) coatings.