Seamless steel tubes for structural purposes

 GB/T 8162
 10, 20, 35, 45,
 40Cr, 35CrMo

 Seamless steel tubes for liquid service

 GB/T 8163
 10, 20, Q345B

 Seamless steel tubes for low and medium pressure

 GB3087
 10, 20

 Seamless steel tubes and for high pressure boiler

 GB5310
 20G, 12CrMoG,
 15CrMoG, 15MoG,
 12Cr2MoG, 20MoG,
 12Cr1MoVG

 Carbon carbon — manganese steel seamless tubes and pipes for ship

 GB/T 5312
 C10, C20

 Seamless steel tubes for high pressure

 GB6479
 10, 20, 16Mn
 12CrMo, 15CrMo

 Seamless steel tubes for petroleum cracking

 GB9948
 10, 20,
 12GrMo, 15GrMo

 Cold — drawn or cold — rolled precision seamless steel tubes

 GB/T3639
 10,20,35,45
 Q345B