This Standard for gray iron threaded fittings, Classes 125 and 250 covers: (a) pressure-temperature ratings (b) size and method of designating openings of reducing fittings (c) marking (d) material (e) dimensions and tolerances (f) threading, and (g) coatings
ASME B16.4-2006 history
2022ASME B16.4-2021 Gray Iron Threaded Fittings classes 125 and 250
2016ASME B16.4-2016 Gray Iron Threaded Fittings: Classes 125 and 150
2011ASME B16.4-2011 Gray Iron Threaded Fittings: Classes 125 and 250
2006ASME B16.4-2006 Gray Iron Threaded Fittings Classes 125 and 250
1998ASME B16.4-1998 Gray iron threaded fittings; Classes 125 and 250