API 5CT J55 Pipe

API 5CT J55 Pipe: Technical Guide (Based on API Spec 5CT Latest Edition)

J55 belongs to Group 1 carbon steel grades in API 5CT classification, along with H40, K55, N80, and P110 (depending on PSL level).

Grade meaning: "55" refers to nominal minimum yield strength of 55 ksi (379 MPa)

Yield strength range: 379–552 MPa (typical API specification range)

Governing Standards

API Spec 5CT (Latest Edition) – Casing and Tubing Standard

API Spec 5B – Threading, gauging, and thread inspection

Product Specification Levels

PSL1

PSL2

⚠️ Note: API 5CT does not define PSL3.

Product Types

Casing pipe

Tubing pipe

Manufacturing Types

Seamless (SMLS) – primary production method

Welded (ERW/HFW) – limited use depending on manufacturer capability and size range

 

J55 Casing Tubing Dimensions

API 5CT J55 Casing Dimensions Table
OD (inch)	W.T. (mm)	Weight (lb/ft)
4-1/2″	5.21	9.5
4-1/2″	5.69	10.5
4-1/2″	6.35	11.6
4-1/2″	7.37	13.5
4-1/2″	8.56	15.1
5″	5.59	11.5
5″	6.43	13
5″	7.52	15
5″	9.19	18
5″	11.1	21.4
5-1/2″	6.2	14
5-1/2″	6.98	15.5
5-1/2″	7.72	17
5-1/2″	9.17	20
5-1/2″	10.54	23
6-5/8″	7.32	20
6-5/8″	8.94	24
6-5/8″	10.59	28
6-5/8″	12.06	32
7″	5.87	17
7″	6.91	20
7″	8.05	23
7″	9.19	26
7″	10.36	29
7″	11.51	32
7″	12.65	35
7″	13.72	38
7-5/8″	7.62	24
7-5/8″	8.33	26.4
7-5/8″	9.52	29.7
7-5/8″	10.92	33.7
7-5/8″	12.7	39
7-5/8″	14.27	42.8
7-5/8″	15.88	47.1
8-5/8″	6.71	24
8-5/8″	7.72	28
8-5/8″	8.94	32
8-5/8″	10.16	36
8-5/8″	11.43	40
8-5/8″	12.7	44
8-5/8″	14.15	49
9-5/8″	7.92	32.3
9-5/8″	8.94	36
9-5/8″	10.03	40
9-5/8″	11.05	43.5
9-5/8″	11.99	47
9-5/8″	13.84	53.5
9-5/8″	15.11	58.4
10-3/4″	7.09	32.75
10-3/4″	8.89	40.5
10-3/4″	10.16	45.5
10-3/4″	11.43	51
10-3/4″	12.57	55.5
10-3/4″	13.84	60.7
10-3/4″	15.11	65.7
13-3/8″	8.38	48
13-3/8″	9.65	54.5
13-3/8″	10.92	61
13-3/8″	12.19	68
13-3/8″	13.06	72

 

API 5CT J55 Tubing Dimensions Table
OD (inch)	Weight (lb/ft)	WT (mm)
1.9″	2.75	3.18
2-3/8″	4.7	3.18
2-3/8″	5.95	4.85
2-7/8″	6.4	4.83
2-7/8″	6.5	5.51
2-7/8″	7.9	6.45
3-1/2″	9.2	5.74
3-1/2″	10.3	6.35
4″	11	6.02
4-1/2″	12.6	6.52
4-1/2″	12.75	6.88

 

Tolerance Requirements

Wall thickness tolerance: ±12.5% (API standard)

Surface defect limits: controlled per API acceptance criteria

 

Thread & End Finish Types

Tubing End Finish

NU (Non-Upset)

EU (External Upset)

IJ (Integral Joint)

Casing Thread Types

STC (Short Round Thread)

LTC (Long Round Thread)

BTC (Buttress Thread)

Premium proprietary connections (project-specific)

⚠️ Note: "E = Extreme Premium Thread" is not an API-defined code.

Send OD, thickness, and depth - we recommend the right grade within 24h.

 

API 5CT J55 Tube Chemical Composition

J55 is a low-carbon steel grade without mandatory alloying elements such as Cr, Ni, or Mo.

Grade	C	Si	Mn	P	S	Cr	Ni	Cu	Mo
API 5CT J55	0.34-0.39	Controlled by manufacturer (no fixed API maximum)	1.25-1.50	≤ 0.030%	≤ 0.030%	0.15	0.20	0.20	/

 

API 5CT J55 Pipe Mechanical Property

Steel Grade	Yield Strength (Mpa)	Tensile Strength (Mpa)	Total Elongation Under Load %
API 5CT J55	379-552(55 ksi nominal)	≥517(75 ksi)	0.5

 

Comparison: API 5CT J55 vs K55

Item	J55	K55
Yield Strength	379–552 MPa	379–552 MPa
Minimum Tensile Strength	≥ 517 MPa	≥ 655 MPa
Elongation	≥ 19%	≥ 15%
Typical Usage	Low-cost shallow wells	Higher strength shallow wells
Color Marking	Green band	Green band (variant markings may apply)

 

API 5CT J55 Casing Pipe

 

Pipe Process of API 5CT J55 Casing

Round Pipe -- pipe inspection - NDTinspection MPI -- End Threading -- Thread lnspection --Coupling Threadingnspection -- NDT inspection MP1( coupling) -- Phosphating (for coupling) - Coupling power Make up -- Hydrostatic test-- Drift test -- Doping and Protectors Application - Coating --Measurement of Length and Weight -- Colourdentification - Marking --Packing - Warehousing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Heat Treatment & PSL Differences

PSL1

Heat treatment: determined by manufacturer process (not mandatory full-length normalization)

Inspection: basic dimensional and visual inspection

NDT: not mandatory full-body ultrasonic testing

 

PSL2

PSL2 requires higher quality control:

Mandatory heat treatment (e.g., normalization or quenching & tempering depending on mill process)

Mandatory non-destructive testing (NDT)

Mechanical impact testing requirements (e.g., Charpy V-notch where applicable)

Strict traceability and inspection documentation

 

API Color Marking System for J55

Color marking is used for field identification.

J55 tubing: green band marking (industry standard practice)

J55 casing: green band marking with coupling identification markings

⚠️ Note: Exact band configurations may vary slightly by manufacturer but must comply with API identification rules.

 

Inspection & Testing Requirements

All J55 casing and tubing must pass the following tests (depending on PSL level):

Visual inspection (surface defects, cracks, seams)

Dimensional inspection (OD, WT, length, straightness)

Mechanical tensile testing (yield, tensile strength, elongation)

Chemical composition analysis (spectrometric testing)

Hydrostatic pressure test

Flattening test (welded pipe)

Bend test (for welded products if applicable)

NDT testing (UT / EMI / flux leakage – PSL2 mandatory)

Drift test (internal clearance verification)

 

Application Scope & Service Limitations

Suitable Applications

Shallow oil & gas wells

Low-pressure production wells

Water wells

Geothermal shallow drilling

Piling and foundation casing applications

 

Unsuitable Applications

Deep wells with high pressure or high collapse loads

Sour service environments containing H₂S

High-temperature corrosive formations

⚠️ J55 is not designed for sour service applications.

 

API 5CT Casing and Tubing Certificate

 

API 5CT OCTG Pipe Supplier

 

Gnee pipe participated in the NECC exhibition

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OCTG Pipe Customers

 

API OCTG Test and inspection

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API 5CT OCTG Factory

Check Stock Availability & Delivery Time Now

 

FAQ

Q1: What standard governs J55 casing and tubing?

API Spec 5CT (latest edition) together with API Spec 5B for threading and gauging.

 

Q2: Can J55 be used for both casing and tubing?

Yes. J55 is used for both casing and tubing depending on size and well design requirements.

 

Q3: What is the difference between PSL1 and PSL2?

PSL1 has basic manufacturing and inspection requirements. PSL2 requires stricter testing, including mandatory NDT and additional mechanical testing.

 

Q4: Is J55 suitable for sour service (H₂S)?

No. J55 is not designed for sour service environments. For sour service, grades such as L80, T95, or C90 should be used.

 

Q5: What manufacturing types are available?

Primarily seamless (SMLS). Welded pipe may be used in limited large-diameter applications depending on mill capability.

 

Q6: Why is J55 marked green?

Green color marking is used in API practice to identify Group 1 low-strength grades such as J55 and K55 for field recognition.

 

Q7: What is the weight formula for steel pipe?

Weight (kg/m) ≈ 0.02466 × (OD − WT) × WT

 

Q8: What thread types are available?

STC, LTC, BTC, and various proprietary premium connections depending on project requirements.

 

Key Advantages of API 5CT J55 Pipe

Cost-effective OCTG solution for shallow wells

Good weldability and formability

Stable mechanical performance for low-pressure applications

Globally standardized according to API 5CT

Wide availability across casing and tubing sizes

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