Seat Spring (valve part) certificate:ISO9001:2008,CE,etc Seat Spring (valve part) Specification: Wire diameter: 0.18mm-50mmStyle: coilCertificate:ISO9001:2008,CE,etc Material: A313-304, Inconel X-750, etc.62Si2MnA,65Mn,SUS301,304 Seat Spring (valve part)