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
Chemical Composition of API 5CT
| Grade | C≤ | Si≤ | Mn≤ | P≤ | S≤ | Cr≤ | Ni≤ | Cu≤ | Mo≤ | V≤ | Als≤ |
| 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 |
| 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 |
| 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 |
| 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 |
| 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) |
| J55 | 379-552 | ≥517 |
| K55 | ≥655 | ≥517 |
| N80 | 552-758 | ≥689 |
| L80 | 552-655 | ≥655 |
| P110 | 758-965 | ≥862 |