... 4)Surface Polishment and NDT Test 5)ISO9001:2 Gate Valve StemsStandard: ASTM, BF,BS, JIS, UNI, ANSI, ... Malleable Iron etc.2) Process: Investment Casting, Sand Casting (Resin Sand Casting, Green Sand Casting), Permanent Casting, Die Casting, Centrifugal Casting, Forging and Stamping etc.3) ... : ASTM, BF,BS, JIS, UNI, ANSI, ISO etc.valve stem of 303 stainless steel4"API Gate ValveMaterial: Alloy Steel ...