What is API J55 EUE pipes for borewell system
May 25, 2026
API J55 EUE pipes are highly cost-effective tubular solutions specifically designed for borewell systems, including deep water, geothermal, and shallow oil/gas wells. Utilizing the J55 steel grade, which offers a yield strength of 55,000–80,000 psi (379–552 MPa) and a minimum tensile strength of 75,000 psi (517 MPa), these pipes reliably handle the formation pressures of shallow to medium-depth wells.
The defining EUE (External Upset End) connection features a thickened-end design that ensures the joint strength exceeds that of the pipe body, effectively preventing disconnection or structural failure under the heavy weight of long pipe strings or submersible pumps. This makes it an industry-standard choice that perfectly balances economic value with exceptional tensile stability and sealing performance.
J55 identification API color code
J55 Tubing: One bright green band, coupling bright green and no bands.
API 5CT J55 Oil Tubing Chemical Composition
| Grade | C | Si | Mn | P | S | Cr | Ni | Cu | Mo |
| 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 | / |
API 5CT J55 Oilfield Tubing Mechanical Property
| Steel Grade | Yield Strength (Mpa) | Tensile Strength (Mpa) | Total elongation under load % |
| API 5CT J55 | 379-552 | ≥517 | 0.5 |
API 5CT J55 Seamless Oil Pipe Size Chart
| Outer Diameter | Wall Thickness | Weight | Grade | Threaded | Length | |
| in | mm | kg/m | lb/ft | |||
| 4 1/2″ | 114.3 | 14.14-22.47 | 9.50-11.50 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 5″ | 127 | 17.11-35.86 | 11.50-24.10 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 5 1/2″ | 139.7 | 20.83-34.23 | 14.00-23.00 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 6 5/8″ | 168.28 | 29.76-35.72 | 20.00-24.00 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 7″ | 177.8 | 25.30-56.55 | 17.00-38.00 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 7 5/8″ | 193.68 | 35.72-63.69 | 24.00-42.80 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 8 5/8″ | 219.08 | 35.72-72.92 | 24.00-49.00 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 9 5/8″ | 244.48 | 48.07-86.91 | 32.30-58.40 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 10 3/4″ | 273.05 | 48.73-97.77 | 32.75-65.70 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 11 3/4″ | 298.45 | 62.50-89.29 | 42.00-60.00 | J55 | LTC/STC/BTC | R1/R2/R3 |
| 13 3/8″ | 339.72 | 71.43-107.15 | 48.00-72.00 | J55 | LTC/STC/BTC | R1/R2/R3 |
API 5CT J55 Oil Well Drilling Casing Pipe Tolerance
| Item | Allowable tolerance | |
| Outer diameter | Pipe body | D≤101.60mm±0.79mm |
| D≥114.30mm+1.0% | ||
| -0.5% | ||
| Wall thickness | -12.5% | |
| Wight | Single piece | +6.5%+3.5% |
| Total weight | -1.75 | |
Test and inspection of API J55 EUE pipes for borewell system
Mechanical & Chemical Testing (Material Integrity)
These tests confirm that the steel grade J55 meets the basic structural requirements.
| Test Type | API 5CT Requirement | Purpose |
| Tensile Test | Yield: 55–80 ksi; Tensile: Min 75 ksi | Ensures the pipe can support the hanging weight of the pump and string. |
| Flattening Test | Mandatory for ERW pipes | Checks the quality of the weld seam to ensure it won't crack under pressure. |
| Chemical Analysis | P ≤ 0.030%, S ≤ 0.030% | Limits impurities to prevent brittleness and ensure long-term durability. |
Dimensional Inspection (Geometry & Fit)
Precise dimensions are critical for borewell systems to ensure the pipe fits the borehole and equipment.
| Inspection Item | Method / Standard | Importance for Borewells |
| OD & Wall Thickness | Calipers / Micrometers | Ensures consistency and pressure resistance. |
| Drift Test | Mandrel passed through pipe | Critical: Ensures the submersible pump or internal tools can pass through freely. |
| Upset Inspection | Visual & Gauge check | Checks the EUE (External Upset) area for smooth transitions and proper thickness. |
| Length Measurement | Range 1, 2, or 3 | Used to calculate the exact depth of the pump setting. |
Non-Destructive Testing & Pressure Testing (Leak Prevention)
These tests ensure the pipe is "gas-tight" and "water-tight" without damaging the material.
| Test Type | Description | Purpose |
| Hydrostatic Test | Every pipe is filled with water at high pressure | Mandatory. Ensures no leaks in the pipe body or EUE connection. |
| NDT (Ultrasonic/Eddy) | Ultrasonic (UT) or Magnetic Particle (MPI) | Detects hidden internal flaws or cracks in the weld/body. |
| Visual Inspection | Surface check by trained inspectors | Checks for pits, gouges, or scale that could lead to corrosion in water. |
Thread & Connection Inspection (API 5B)
Since EUE is a threaded connection, the integrity of the joint is paramount to prevent the pipe string from falling into the well.
| Item | Inspection Detail | Requirement |
| Thread Gauging | Lead, Taper, and Height | Ensures the EUE threads match perfectly with the coupling. |
| Standoff / Hand-tight | Manual check of thread engagement | Verifies that the connection will achieve a proper seal when torqued. |
| Thread Visual | Inspection for burrs or torn threads | Prevents "galling" (stripping) during installation at the well site. |
GNEE API J55 EUE pipes for borewell system Factory
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GNEE API J55 EUE pipes for borewell system Certificate
FAQ
What is the yield strength of J55 tubing?
The yield strength of J55 tubing is:
Minimum: 55,000 psi (379 MPa)
Maximum: 80,000 psi (552 MPa)
What is the chemical composition of J55?
According to the API 5CT specification, the chemical composition of J55 is primarily focused on limiting impurities to ensure weldability and durability. It is a carbon-manganese steel with the following requirements:
Phosphorus (P): Maximum 0.030%
Sulfur (S): Maximum 0.030%
Carbon (C), Manganese (Mn), and Silicon (Si): There are no strictly defined numerical limits in the API table for these elements; they are adjusted by the manufacturer to ensure the pipe reaches the required mechanical strengths (55,000 psi yield).
What is J55 steel?
J55 steel is the most common and economical grade of carbon steel used for casing and tubing in the oil and gas industry, governed by the API 5CT standard.
