● 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 | |||||
