... -199910, 20ASTM A179, ASTM A192 ASTM SA179,SA192, BS3059Seamless Steel Tubes for high pressure --Chemical fertilizer equipmentGB6479-8610, 20G, Q345, Q390, 10MoVNb, 12CrMo, 15CrMo, ... -1997 ASTM A161-94Seamless steel tubesfor petroleum crackingGB9948-8610, 20, 12CrMo, 15CrMo, 1Cr2Mo, 1Cr5Mo, JIS G3441-1988 stainless seamless steel tube 300 series