K55 / J55 Seamless Casing Pipe – Strong, Economical, Full Well Condition Adaptability
Product Introduction
K55 and J55 are the most widely used carbon-manganese steel grades for seamless casing pipes, strictly manufactured according to API 5CT (11th Edition) and ISO 11960. Both grades offer good weldability, threadability, and corrosion resistance, suitable for onshore & offshore oil/gas wells, CBM wells, geothermal wells, and water injection wells.
J55: Conventional economic grade for shallow to medium-depth wells, low-pressure formations.
K55: Slightly higher strength than J55, suitable for moderately stressed or medium-depth wells.
Mechanical Properties
| Property | J55 | K55 |
|---|---|---|
| Yield Strength (psi) | 55,000 – 80,000 | 55,000 – 80,000 |
| Yield Strength (MPa) | 379 – 552 | 379 – 552 |
| Tensile Strength (psi) | ≥ 75,000 | ≥ 95,000 |
| Tensile Strength (MPa) | ≥ 517 | ≥ 655 |
| Elongation (2″ gauge) | ≥ 20% | ≥ 20% |
| Hardness (HRC) | ≤ 23 | ≤ 24 |
| Impact Energy (0°C, J) | ≥ 27 | ≥ 27 |
Key difference: K55 has significantly higher tensile strength, offering better overload resistance.
Size Range & Thread Types
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | 2″ – 20″ (60.3 mm – 508 mm) |
| Wall Thickness (WT) | 0.055″ – 1.602″ (1.65 mm – 26.97 mm) |
| Thread Types | STC, LTC, BTC, EU, NU |
Key Advantages
● Seamless Manufacturing, Structural Integrity
Hot-rolled piercing + controlled cooling/cold drawing process – no weld seam defects.
Tight wall thickness tolerance.
● Excellent Burst & Collapse Resistance
Collapse resistance tables available per grade & WT.
Each pipe hydrostatically tested per API requirements.
● Reliable Thread Seal & Galling Resistance
Threads are phosphated or copper-coated to reduce friction during make-up.
Thread protectors provided for shipping.
● Wide Application Scope
Conventional oil & gas wells
Water injection & observation wells
Low to medium pressure gas wells
Surface, intermediate, and production casing
Optional Treatments
Corrosion protection: External black paint or transparent anti-rust oil.
Sour service: NACE MR0175 / ISO 15156 compliant (hardness & composition control) for H₂S environments.
NDT methods: 100% UT or ET, optional flux leakage inspection.
Quality Assurance System
Spectrochemical analysis per heat.
Hydrostatic test, dimensional check (OD, WT, thread profile) on each pipe.
Traceable Mill Test Certificate (EN 10204 Type 3.1 or 3.2).
Certifications: API 5CT Monogram, ISO 9001, ISO 14001, OHSAS 18001.
Int'l Department add
Rm1406, 14th/F Legu Business Center, Xihu Ave,Hongqi Rd, Nankai Dist, Tianjin City, China
whatsapp Number
0086 18233409873
lucky@tjshenzhoutong.com
Hot Tags: k55 / j55 seamless casing pipe, China k55 / j55 seamless casing pipe manufacturers, suppliers, factory, api 5l seamless steel pipe, seamless pipe for irrigation, seamless pipe for plug connection, seamless pipe for response system connection, seamless pipe for shipbuilding, Seamless Steel Pipe ASTM A53 A106 Pipe
