API 5CT Casing
Introduction
Specification
Application: Used as the structural retainer for the walls of oil, gas wells
Specification: OD: 4 1/2’’ ~ 20’’ (114.3mm ~ 508mm)
WT: 0.205’’ ~ 0.635’’ (5.21mm ~ 16.13mm)
LENGTH: R1, R2, R3
Standard: API 5CT J 55/K55/N80/C75/L80/C90/T95/Q125
Process Type: Seamless (SMLS), Electric Resistance Welded (ERW)
End: Beveled, Square Cut, With LTC/STC/BTC/VAM Connection
Surface: Anti-corrosion Water Based Paint
Packing: Protection Caps in both end, Waterproof Paper Wrapped, Two Tags
Tolerance
Chemical Composition
Mechanical Properties
| Types of steel tubes | Outer Diameter | Wall Thickness | |
| Cold-rolled tubes | Tube sizes(mm) | Tolerances(mm) | Tolerances(mm) |
| ＜114.3 | ±0.79 | －12.5% | |
| Standard | Grade | Chemical compositions（％） | |||||||||
| API SPEC 5CT | J55 | C | Si | Mn | P | S | Cr | Ni | Cu | Mo | V |
| K55 | 0.34～0.39 | 0.20～0.35 | 1.25～1.50 | ≤0.020 | ≤0.015 | ≤0.15 | ≤0.20 | ≤0.20 | / | / | |
| N80 | 0.34～0.38 | 0.20～0.35 | 1.45～1.70 | ≤0.020 | ≤0.015 | ≤0.15 | / | / | / | 0.11～0.16 | |
| L80 | 0.15～0.22 | ≤1.00 | 0.25～1.00 | ≤0.020 | ≤0.010 | 12.0～14.0 | ≤0.20 | ≤0.20 | / | / | |
| P110 | 0.26～0.395 | 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 | |
| Grade | Type | Total elongation under load (%) | Yield strength (min) | Yield strength (max) | Tensile strength min Mpa | Hardness Max (HRC) | Hardness Max(HBW) |
| J55 | - | 0.5 | 379 | 552 | 517 | - | - |
| K55 | - | 0.5 | 379 | 552 | 655 | - | - |
| N80 | 1 | 0.5 | 552 | 758 | 689 | - | - |
| N80 | Q | 0.5 | 552 | 758 | 689 | - | - |
| L80 | 1 | 0.5 | 552 | 655 | 655 | 23 | 241 |
| L80 | 9Cr | 0.5 | 552 | 655 | 655 | 23 | 241 |
| L80 | 13Cr | 0.5 | 552 | 655 | 655 | 23 | 241 |
| C90 | - | 0.5 | 621 | 724 | 689 | 25.4 | 255 |
| C95 | - | 0.5 | 655 | 758 | 724 | - | - |
| T95 | - | 0.5 | 655 | 758 | 724 | 25.4 | 255 |
| P110 | - | 0.6 | 758 | 965 | 862 | - | - |
| Q125 | All | 0.65 | 862 | 1034 | 931 | - | - |
