Welded Square Steel Tubes Square Steel Tubes O.D:1mmX1mm--- ... .T:0.2mm---50mm SPOTS GOODS AT PRESENT: 2864.57 Welded Square Steel Tubes 1. Grade: 12Cr1Mov, 12CrMo,15CrMo, 13CrMo44, ... standard of SY/T5037-2000, GB/T9711.1-1997 and API SPEC 5L, the material can be Q235AB, 16Manganese and X42 ... /3, DIN 1629/4, ASTM A53-2007, ASTM A210-1996, API 5LGrade16Mn, ST35-ST52, Q195-Q345Grade16Mn, St37, St52, St52.4, ...