... : ISO9001-2008; Standard: ASTM, JIS, DIN, ANSI, BS Ball Valve Stem Description: Size : 1/2" to 36"Certification: ISO 9001: ... , 201 . Standards for the machining screw thread :PT, NPT, DIN2999, BS84, IS0228, JISB0203, JISB0207, JISB0211.Perfect Quality, On Time Delivery! Ball Valve Stem