Features: 1) American standard a) Materials: ANSI/ASME A197-79 b) Dimensions:ANSI/ASME B16.3-85 c) Threads: ANSI/ASME B1.20.1 2) Din Standard a) Materials: DIN1692 b) Dimensions:DIN2950 c) Threads: DIN2999 3) British Standard: a) Materials: ISO 5922 b) Dimensions: ISO 49 c) Threads: ISO 7/1