API L80 Casing
Data under reviewL80 is the sour-service-capable API 5CT grade: same 80 ksi class as N80 but with a controlled yield window and a 23 HRC hardness cap that resists sulfide stress cracking. Type 1 is the standard Cr-free version; 9Cr and 13Cr types cover corrosive CO2 service.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.43 (Type 1) |
| Mn | ≤1.90 (Type 1) |
| P | ≤0.030 |
| S | ≤0.030 |
| Note | Hardness capped at 23 HRC for sour-service suitability |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Yield strength | 552–655 MPa (80–95 ksi, controlled band) |
| Tensile strength | ≥655 MPa (95 ksi) |
| Hardness | ≤23 HRC |
| Density | 7.85 g/cm³ |
Heat treatment
Quenched and tempered; hardness survey per API 5CT is mandatory for the grade.
Equivalent grades
| Standard | Designation |
|---|---|
| aisi | API 5CT L80 (Type 1) |
| gb | L80 (GB/T 19830) |
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Production casing/tubing in H2S-bearing wells, gas storage wells.
Processing: Order to NACE MR0175/ISO 15156 when sour; keep welding off the pipe body — connections are threaded.
FAQ
- L80 vs N80 — same strength, what differs?
- L80 adds a maximum yield (655 MPa) and a 23 HRC hardness limit for SSC resistance, plus Q&T delivery; N80 has no hardness cap and must not be used in sour wells.
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Ask for a quotationVisit NasteelSource: API 5CT published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.