API 5L X56
Data verifiedX56 fills the gap between the mass-market X52 and the high-strength X60/X65 trunk-line grades. Regional transmission and offshore specifications — particularly in the Middle East and Latin America — standardised on its 56 ksi yield for medium-wall pipelines.
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 | ≥390 MPa (56,600 psi) |
| Tensile strength | 490–760 MPa (PSL2) |
| Density | 7.85 g/cm³ |
Heat treatment
TMCP or normalized; PSL2 toughness mandatory, sour-service variants add HIC/SSC testing.
Equivalent grades
| Standard | Designation |
|---|---|
| din | L390 (near) |
| aisi | API 5L X56 (PSL2) |
| gb | L390 (GB/T 9711) |
Compare side by side: API 5L X56 vs API 5L X52 · API 5L X56 vs API 5L X60
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Regional gas transmission, offshore risers and flowlines (with supplementary testing), oil trunk lines.
Processing: Standard X-grade field welding practice; for sour or offshore duty, order PSL2 with the relevant annexes (HIC, DWTT, fracture toughness).
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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.