Special Seamless steel pipe factory for ship ,project ,machine part and so on .Materials and standard is API 5L Gr.B /ASTM A106 Gr.B /ASTM A53 Gr.B/ GOST8732 CT20/GOST8731 CT20 /GOST8732 CT45
/STPG370/DIN 1629 ST44/ST52/S355/S235/S275/Q345 /ASTM A53 Gr.B/ GOST8732 CT20/GOST8731 CT20 /GOST8732 CT45 /STPG370/DIN 1629 ST44/ST52/S355/S235/S275/Q345