... 5.Certificate:API,ISO,CE,eg astm a105n carbon steel weld neck flange size 1/2" to 24 ... Class A, B, C, D, EstandardASME B16.5, ASME B16.47, ASME B16.36,DIN2505,EtcMaterialCarbon steel(ASTM A105 ... ,Q235,A350LF2,A350LF3,Etc)Stainless steel(ASTM A182 F304, F304L, ... F347,F310F44F51,A276 S31803, A182, F43,Etc)Alloy steel(ASTM A694 F42,F46,F52,F56,F60,F65,F70 ...