API Spec 5CT – Specification 5CT/ISO 11960, Specification for Casing and Tubing, Eighth Edition, Petroleum and natural gas industries-Steel pipes for use as casing or tubing for wells.
Standard: API SPEC 5CT
API 5CT pipe Size (mm):
- Outer Dimensions: 6.0mm – 219.0mm
- Wall Thickness: 1.0mm – 30 mm
- Length: max 12000mm
Application: gas, water and oil transportation in both oil and natural gas .
The main steel grade of API 5CT:
- API 5CT J55, API 5CT K55, API 5CT N80, API 5CT L80, API 5CT P110.
Packing: Bare/bundles/crates/crate protection at the both sides of tubes or as per customers’ requirements .
This International Standard is applicable to the following connections in accordance with ISO 10422 or API Spec 5B:
- short round thread casing (STC);
- long round thread casing (LC);
- buttress thread casing (BC);
- extreme-line casing (XC);
- non-upset tubing (NU);
- external upset tubing (EU);
- integral joint tubing (IJ).
For such connections, this International Standard specifies the technical delivery conditions for couplings and thread protection.
For pipes covered by this International Standard, the sizes, masses, wall thicknesses, grades and applicable end finishes are defined.
This International Standard may also be applied to tubulars with connections not covered by ISO/API standards.
2. Chemical Composition
| Grade | C≤ | Si≤ | Mn≤ | P≤ | S≤ | Cr≤ | Ni≤ | Cu≤ | Mo≤ | V≤ | Als≤ |
| API 5CT J55 | 0.34-0.39 | 0.20-0.35 | 1.25-1.50 | 0.020 | 0.015 | 0.15 | 0.20 | 0.20 | / | / | 0.020 |
| API 5CT K55 | 0.34-0.39 | 0.20-0.35 | 1.25-1.50 | 0.020 | 0.015 | 0.15 | 0.20 | 0.20 | / | / | 0.020 |
| API 5CT N80 | 0.34-0.38 | 0.20-0.35 | 1.45-1.70 | 0.020 | 0.015 | 0.15 | / | / | / | 0.11-0.16 | 0.020 |
| API 5CT L80 | 0.15-0.22 | 1.00 | 0.25-1.00 | 0.020 | 0.010 | 12.0-14.0 | 0.20 | 0.20 | / | / | 0.020 |
| API 5CT J P110 | 0.26-035 | 0.17-0.37 | 0.40-0.70 | 0.020 | 0.010 | 0.80-1.10 | 0.20 | 0.20 | 0.15-0.25 | 0.08 | 0.020 |
Mechanical Properties of API 5CT
| Steel Grade | Yield Strength (Mpa) | Tensile Strength (Mpa) |
| API 5CT J55 | 379-552 | ≥517 |
| API 5CT K55 | ≥655 | ≥517 |
| API 5CT N80 | 552-758 | ≥689 |
| API 5CT L80 | 552-655 | ≥655 |
| API 5CT P110 | 758-965 | ≥862 |
API Spec 5CT standard replaced by:
- API Spec 5CT – Specification 5CT/ISO 11960, Specification for Casing and Tubing, Eighth Edition, Petroleum and natural gas industries-Steel pipes for use as casing or tubing for wells
- This product references:
- API Spec 5B – Specification for Threading, Gauging, and Thread Inspection of Casing, Tubing, and Line Pipe Threads (US Customary Units) (Includes March 2004 Addendum)
- ISO 10422:1993 – Petroleum and natural gas-industries; threading, gauging, and thread inspection of casing, tubing and line pipe threads; specification
- This product replaces:
- API 5CT – Specification for Casing and Tubing (U.S. Customary Units)
- ISO 11960 was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore structures for petroleum, petrochemical and natural gas industries, Subcommittee SC 5, Casing, tubing and drill pipe.
