API 5L X65
Data verifiedAPI 5L X65 is the mainstream high-grade line pipe for modern gas transmission, including many of the large-diameter Chinese and transcontinental projects. It offers X70-class economics in milder designs with easier welding than the highest grades.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.24 (PSL2) |
| Si | ≤0.45 |
| Mn | ≤1.65 (PSL2) |
| P | ≤0.025 |
| S | ≤0.015 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Yield strength | ≥450 MPa (65,000 psi) |
| Tensile strength | 535–760 MPa (PSL2) |
| Density | 7.85 g/cm³ |
Heat treatment
TMCP; sour-service variants (X65MS) add HIC/SSC testing and tighter chemistry.
Equivalent grades
| Standard | Designation |
|---|---|
| din | L450 (near) |
| aisi | API 5L X65 (PSL2) |
| gb | L450 (GB/T 9711) |
Compare side by side: API 5L X65 vs API 5L X60 · API 5L X65 vs API 5L X70
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Gas trunk pipelines, subsea pipelines, high-pressure laterals.
Processing: Low-carbon TMCP chemistry welds readily; for sour service order the M/S suffix grades with HIC-tested plate.
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Ask for a quotationVisit NasteelSource: API 5L published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.