steel welded pipe tube Stankard:ASTM A312/A312M Grade:TP304,TP304LTP32 1,TP3 16Ti,TP310S,etc. Manufacture process:cold d steel welded pipes tubeStankard:ASTM A312 ... process:cold draw or cold roll,Anne aled,and pickled.steel welded pipes tubeStankard:ASTM A312/A312MGrade:TP304,TP304LTP321,TP316Ti,TP310S,etc ...