中文版 (Chinese): README_cn.md
API LC stands for Long-thread Coupling: API round-thread casing (long thread) with a standard coupling, manufactured to API 5CT (product specification) and API 5B (thread gauging).
For every size (OD × wall × grade) combination there are two mirrored editions:
| Edition | Language | Unit system | Directory |
|---|---|---|---|
| CN / SI | 中文 (Chinese) | SI — mm, MPa, kN, kg/m | LC_SI_CN/ |
| EN / USC | English | US Customary — in, psi, lbf, lb/ft | LC_USC_EN/ |
Both editions carry identical engineering content; only the language and units differ.
44 OD × wall-thickness combinations, 646 datasheets per unit system.
| Nominal OD (mm / in) | Wall thickness (mm) |
|---|---|
| 114.3 / 4.500 | 6.35, 7.37, 8.56 |
| 127.0 / 5.000 | 6.43, 7.52, 9.19, 11.1, 12.14, 12.7 |
| 139.7 / 5.500 | 6.98, 7.72, 9.17, 10.54 |
| 168.28 / 6.625 | 7.32, 8.94, 10.59, 12.06 |
| 177.8 / 7.000 | 8.05, 9.19, 10.36, 11.51, 12.65, 13.72 |
| 193.68 / 7.625 | 8.33, 9.52, 10.92, 12.7, 14.27, 15.11, 15.88 |
| 219.08 / 8.625 | 8.94, 10.16, 11.43, 12.7, 14.15 |
| 244.48 / 9.625 | 8.94, 10.03, 11.05, 11.99, 13.84, 15.11 |
| 508.0 / 20.000 | 11.13, 12.7, 16.13 |
Grades
- API standard grades: H40, J55, K55, M65, L80-1, N80-1, N80-Q, C90, T95, R95, P110, Q125
- Baosteel BG series (sour / special service): BG80S, BG80SS, BG90S, BG90SS, BG95S, BG95SS, BG110S, BG110SS, BG110T, BG125S
S= sour service (H₂S-resistant),SS= super-sour service,T= high-collapse / special-service variant.
These datasheets are provided for engineering reference only. Performance values are calculated at the 87.5 % minimum wall condition per API standards. For project-specific requirements and the latest values, please consult Baosteel.
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