What is the difference between 9CR and 13Cr OCTG
Apr 01, 2026
The core differences between L80-9Cr and L80-13Cr lie in their chromium content, corrosion resistance, and applicable environments:
L80-13Cr contains 12%-13.5% chromium, significantly superior to L80-9Cr's 8.5%-9.5% chromium content. Therefore, it exhibits better resistance to CO₂ corrosion and is suitable for harsher high-carbon dioxide partial pressure environments.
Simultaneously, L80-13Cr also boasts better toughness and impact resistance than L80-9Cr. Although both belong to the L80 steel grade (minimum yield strength approximately 552 MPa) and are delivered in the same condition, L80-13Cr, due to the addition of molybdenum and nickel, is more difficult to produce and more expensive, and is primarily used in heavily corrosive oil wells.
Cut Your Well Completion Costs – Get Direct Factory Quotes on API 5CT L80-13Cr & 9Cr with Competitive Bulk Pricing.
Chemical Composition & Mechanical Properties Comparison
| Parameter | L80-9Cr (9 Chrome) | L80-13Cr (13 Chrome) |
| Chromium Content (Cr %) | 8.00 - 10.00 | 12.00 - 14.00 |
| Molybdenum (Mo %) | 0.90 - 1.10 | Not Mandated (usually trace) |
| Carbon Content (C %) | ≤ 0.15 | ≤ 0.15 - 0.22 |
| Yield Strength (ksi) | 80 - 95 (552 - 655 MPa) | 80 - 95 (552 - 655 MPa) |
| Tensile Strength (ksi) | ≥ 95 (≥ 655 MPa) | ≥ 95 (≥ 655 MPa) |
| Max Hardness (HRC) | ≤ 22.0 | ≤ 23.0 |
| Elongation | Per API 5CT formula | Per API 5CT formula |
| Delivery Condition | Quenched + Tempered (Q&T) | Quenched + Tempered (Q&T) |
| Color Coding (Bands) | Red + Brown + 2 Yellow | Red + Brown + 1 Yellow |
Corrosion Resistance & Application Environment
| Feature | L80-9Cr | L80-13Cr |
| Primary Protection | CO₂ Corrosion | Strong CO₂ Corrosion |
| CO₂ Resistance | Moderate. Suitable for mildly acidic environments. | Excellent. Forms a dense Chromium Oxide protective layer. |
| H₂S Resistance | Very Poor. Not recommended for Sour Service. | Very Poor. Susceptible to Stress Corrosion Cracking (SCC) in H₂S. |
| Chloride (Cl⁻) Resistance | Good | Sensitive. Prone to pitting corrosion in high-concentration brine. |
| Temperature Range | Up to approx. 150°C (300°F) | Up to 180°C (350°F) |
| Relative Cost | High (Significantly more than L80-1) | Extremely High (3-5x the cost of Carbon Steel) |
API 5CT L80-13Cr / 9Cr Tubing Dimension Table:
| Nominal OD (in) | OD (mm) | Weight (lb/ft) | Wall Thickness (mm) | Drift Diameter (mm) | Remarks / Application |
| 2-3/8" | 60.33 | 4.70 | 4.83 | 48.36 | Suitable for low-flow corrosive wells. |
| 2-7/8" | 73.03 | 6.50 | 5.51 | 60.33 | Industry standard / Most common size globally. |
| 3-1/2" | 88.90 | 9.30 | 6.45 | 75.13 | Suitable for high-production gas wells. |
| 4" | 101.60 | 11.00 | 6.65 | 86.11 | Large bore production tubing. |
| 4-1/2" | 114.30 | 12.75 | 6.88 | 98.22 | Ultra-high production / Deep-well production tubing. |
API 5CT L80-13Cr / 9Cr Casing Dimension Table:
| Nominal OD (in) | OD (mm) | Weight (lb/ft) | Wall Thickness (mm) | Drift Diameter (in/mm) | Remarks / Application |
| 4-1/2" | 114.30 | 11.60 | 6.35 | 3.875" (98.43) | Commonly used as slim-hole production casing. |
| 4-1/2" | 114.30 | 13.50 | 7.37 | 3.795" (96.39) | For use in high-pressure environments. |
| 5-1/2" | 139.70 | 17.00 | 7.72 | 4.767" (121.08) | Mainstream specification for shale gas and gas wells. |
| 5-1/2" | 139.70 | 20.00 | 9.17 | 4.653" (118.19) | High-collapse resistant specification. |
| 7" | 177.80 | 26.00 | 9.19 | 6.151" (156.24) | Deep-well production casing. |
| 7" | 177.80 | 29.00 | 10.36 | 6.059" (153.90) | For high-pressure deep-well applications. |
| 9-5/8" | 244.48 | 40.00 | 10.03 | 8.679" (220.45) | 13Cr is rarely used for this size unless the environment is extremely corrosive. |
GNEE API 5CT L80 Casing and Tubing factory
FAQ
What is L80 material equivalent to?
SAE 4140
L80 (API 5CT) is a medium carbon steel and is equivalent to SAE 4140. We offer L80 Casing Pipe which made up of three materials such as L80-1, L80 9Cr and L80 13Cr. These materials feature consistent mechanical properties but having different heat treatment method and chemical composition.
What is 13Cr L80 material?
13 Chrome L80, UNS S42000, is a quenched and tempered martensitic stainless steel used for corrosion resistance in sweet (CO2) and mildly sour (H2S) environments up to 300°F.
What is L80 grade?
L80 Steel is a high-strength, low-alloy steel primarily used in the oil and gas industry, particularly for tubular applications such as casing and tubing in drilling operations.
What is the difference between J55 and L80 OCTG
J55 and L80 are two different strength grades of oil casing steel under the API 5CT standard. The core difference lies in their mechanical properties, corrosion resistance, and applicable working conditions: L80 has higher strength and stronger corrosion resistance, and is suitable for deep wells and corrosive environments; J55 is a common steel grade with low cost, and is suitable for shallow wells and conventional geological conditions.
