● Standard
GB/T8163-2009 ASTM A53M ASTM A106 Main steel grades: 10, 20, B grade
● Uses
For oil and gas transmission and other fluid transfer
● Size deviation
Steel Tube Types |
Tube size mm | Allowable deviation | ||
Common Grade |
High Grade |
|||
Hot rolled tube | Outer diameter D | All | ± 1% (minimum is ± 0.50mm) | — |
Wall thickness S | All | +15%-12.5% (minimum +0.45/ -0.40 mm) | — | |
Cold-drawn tube | Outer diameter D | 6 ~ 10 | ± 0.20 mm | ± 0.15 mm |
> 10 ~ 30 | ± 0.40 mm | ± 0.20 mm | ||
> 30 ~ 50 | ± 0.45 mm | ± 0.30 mm | ||
> 50 | ± 1% | ± 0.8% | ||
Wall thickness S | ≤ 1 | ± 0.15 mm | ± 0.12 mm | |
> 1 ~ 3 | +15%-10% | +12.5%-10% | ||
> 3 | +12.5%-10% | ± 10% |
Note: Can also be supplied with deviations according to ASTM standards
● Chemical composition, mechanical properties
Standard | Steel grade | Chemical composition (%) | ||||||
C | Mn | Si | Cr | Ni | Cu | P.S | ||
GB/T8163 | 10 | 0.07~0.13 | 0.35~0.65 | 0.17~0.37 | ≤ 0.15 | ≤ 0.30 | ≤ 0.25 | ≤ 0.030 |
20 | 0.17~0.23 | 0.35~0.65 | 0.17~0.37 | ≤ 0.25 | ≤ 0.25 | ≤ 0.25 | ≤ 0.030 | |
Q345 | 0.12~0.20 | 1.20~1.60 | 0.20~0.55 | ≤ 0.030 | ||||
Mechanical properties |
Tensile strength (MPa) | Yield Strength (MPa) | Elongation (%) | |||||
10 | 335~475 | ≥ 205 | ≥ 24 | |||||
20 | 410~550 | ≥ 245 | ≥ 20 | |||||
Q345 | 490~665 | ≥ 325 | ≥ 21 |