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API 5CT Casing Pipe

Name: API 5CT Casing Pipe
Brand: Forever Steel

High strength API 5CT P110 casing pipe for deep well oil drilling operations

Tubería de revestimiento API 5CT Grado J55 N80 con acoplamientos para pozos

External protective coating and thread protectors on API 5CT N80 casing pipes

API 5CT J55 K55 oil casing pipe with BTC LTC STC thread connections

Product Name: API 5CT Casing Pipe, Oil Well Casing Pipe
Pipe Type: Seamless casing pipe, ERW casing pipe
Outer Diameter: 114.3 mm - 508 mm
Wall Thickness: 5.21 mm - 16.13 mm
Length: R1, R2, R3
Grades: J55, K55, N80-1, N80-Q, L80-1, L80-9Cr, L80-13Cr, C90, T95, P110, Q125
Standard: API Spec 5CT, 11th Edition, with applicable Addendum 1 and Errata.
Thread Types: STC, LC/LTC, BC/BTC, XC, VAM, VAM TOP, NEW VAM, HYDRILL CS
Applications: Surface casing, intermediate casing and production casing for oil and gas well drilling

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Overview
Specification
Standard
Process
FAQ

API 5CT Steel Casing (OCTG)

API 5CT casing is the structural pipe used to support and protect the wellbore during drilling and production. The casing design review must consider collapse pressure, internal pressure, tensile load and downhole service conditions together with size, weight, grade, connection and inspection requirements.

1. Technical Specifications

Outside Diameter (OD): 4-1/2" to 20" (114.3mm – 508mm)

Wall Thickness (WT): 5.21mm – 16.13mm

Length Range: R1 (4.88m-7.62m), R2 (7.62m-10.36m),R3 (10.36m-14.63m)

Manufacturing Process: Seamless (SMLS) or Electric Resistance Welded (ERW)

Use the casing dimensions database to check casing dimensions and nominal weights, then confirm the ordered size, wall and drift basis against the purchase specification.

2. API 5CT Casing Steel Grades

We provide a full spectrum of grades categorized by strength and environmental resistance:

Group 1:J55, K55, N80-1, N80-Q

Group 2 (Restricted Yield):L80-1, L80-9Cr, L80-13Cr, C90, T95

Group 3 (High Strength):P110

Group 4:Q125

3. Connection & Threading Types

To ensure leak-proof performance under high pressure, we offer standard and premium connections:

STC(Short Round Thread Casing)

LTC(Long Round Thread Casing)

BTC(Buttress Thread Casing)

Premium Connections:Gas-tight threads for extreme high-pressure or sour service (H2S) environments.

4. Key Application Areas

Surface Casing:Protects freshwater zones and supports the blowout preventer.

Intermediate Casing:Isolates high-pressure zones and unstable formations.

Production Casing:The final conduit for oil and gas production, ensuring long-term well stability.

5. Quality Assurance & Protection

Compliance:Full adherence to API Spec 5CT latest edition; supplied with MTC (EN 10204 3.1).

Testing: Confirm the NDT method and coverage, hydrostatic test and drift requirements against the governing API 5CT edition, grade, purchase order and approved ITP. Inspection reports should identify the applicable method, scope and acceptance basis.

Surface Treatment:External black painting/vanish, color coding as per API standards.

Packaging:Steel strapped bundles with thread protectors (plastic or composite) for secure maritime transit.

Export quotation inputs: alongside the casing size, nominal weight, grade, range and connection, state the quantity, destination country and port, requested Incoterm, delivery window and any named operator or project approval requirement. For Middle East and Africa orders, confirm the proposed mill, connection qualification, inspection documents and shipment terms against the actual project specification.

6. API 5CT Technical Resources

· API 5CT Tubing Guide for Production, Injection and Corrosive Service

· API 5CT Casing and Tubing Complete Guide

· Standard API Threads vs Premium Connections

· API 5CT Pre-Shipment Inspection Checklist

· API 5CT Couplings, Pup Joints and Crossovers

· Surface Casing vs Intermediate vs Production Casing vs Liner

Mechanical Properties of API 5CT Casing Grades

Group	Grade	Type	Total	Yield Strength (Mpa)		Tensile	Hardness max
Group	Grade	Type	%	min.	max.	MPa	HRC	HBW
1	H40	—	0.5	276	552	414	—	—
	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	—	—
	R95	—	0.5	655	758	724	—	—
2	M65	—	0.5	445	586	586	22	235
	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	1	0.5	621	724	689	25.4	255
	T95	1	0.5	655	758	724	25.4	255
	C110	—	0.7	758	828	793	30	286
3	P110	—	0.6	758	965	862	—	—
4	Q125	1	0.65	862	1034	931	—	—
a. In case of dispute, laboratory Rockwell C hardness testing shall be used as the referee method.
b. No hardness limits, but the maximum variation is controlled by manufacturer acc API 5CT.

Chemical Composition of API 5CT Casing Grades

Group	Grade	Type	C		Mn		Mo		Cr		Ni	Cu	P	S	Si
Group	Grade	Type	min.	max.	min.	max.	min.	max.	min.	max.	max.	max.	max.	max.	max.
1	H40	—	—	—	—	—	—	—	—	—	—	—	0.03	0.03	—
	J55	—	—	—	—	—	—	—	—	—	—	—	0.03	0.03	—
	K55	—	—	—	—	—	—	—	—	—	—	—	0.03	0.03	—
	N80	1	—	—	—	—	—	—	—	—	—	—	0.03	0.03	—
	N80	Q	—	—	—	—	—	—	—	—	—	—	0.03	0.03	—
	R95	—	—	0.45	—	1.9	—	—	—	—	—	—	0.03	0.03	0.45
2	M65	—	—	—	—	—	—	—	—	—	—	—	0.03	0.03	—
	L80	1	—	0.43	—	1.9	—	—	—	—	0.25	0.35	0.03	0.03	0.45
	L80	9Cr	—	0.15	0.3	0.6	0.9	1.1	8	10	0.5	0.25	0.02	0.01	1
	L80	13Cr	0.15	0.22	0.25	1	—	—	12	14	0.5	0.25	0.02	0.01	1
	C90	1	—	0.35	—	1.2	0.25	0.85	—	1.5	0.99	—	0.02	0.01	—
	T95	1	—	0.35	—	1.2	0.25	0.85	0.4	1.5	0.99	—	0.02	0.01	—
	C110	—	—	0.35	—	1.2	0.25	1	0.4	1.5	0.99	—	0.02	0.005	—
3	P110	—	—	—	—	—	—	—	—	—	—	—	0.03	0.03	—
4	Q125	1	—	0.35	—	1.35	—	0.85	—	1.5	0.99	—	0.02	0.01	—
a. The carbon content for L80 may be increased up to 0, 50 % maximum if the product is oil-quenched.
b. The molybdenum content for Grade C90 Type 1 has no minimum tolerance if the WT is less than 17, 78 mm.
c. The carbon content for R95 may be increased up to 0, 55 % maximum if the product is oil-quenched.
d. The molybdenum content for T95 Type 1 may be decreased to 0, 15 % minimum if the WT is less than 17, 78 mm.
e. For EW Grade P110, the phosphorus content shall be 0,020 % maximum and the sulfur content 0,010 % maximum
NL = no limit. Elements shown shall be reported in product analysis.

API 5CT Casing Dimensional Tolerances

Items		Allowable Deviation
Out Diameter	D ≤ 101.60mm	± 0.79mm
	D ≥ 114.30mm	+ 1.0%, -0.5%
Wall Thickness		-12.50%
Mass (Single Lengths)		+6.5%, -3.5%

API 5CT Casing Size, Weight and Grade Availability

DN	O. D.		Weight		W. T.		End Machining Form
	O. D.		Weight		W. T.		Steel Grade
	Inch	mm	lb/ft	kg/m	Inch	mm	H40	J55	L80	N80	C90	P110
	Inch	mm	lb/ft	kg/m	Inch	mm	H40	K55	L80	N80	T95	P110
4 1/2	4.5	114.3	9.5	14.14	0.205	5.21	PS	PS	–	–	–	–
			10.5	15.63	0.224	5.69	–	PSB	–	–	–	–
			11.6	17.26	0.25	6.35	–	PSLB	PLB	PLB	PLB	PLB
			13.5	20.09	0.29	7.37	–	–	PLB	PLB	PLB	PLB
			15.1	22.47	0.337	9.56	–	–	–	–	–	PLB
5	5	127	11.5	17.11	0.22	5.59	–	PS	–	–	–	–
			13	19.35	0.253	6.43	–	PSLB	–	–	–	–
			15	22.32	0.296	7.52	–	PSLB	PLB	PLB	PLBE	PLB
			18	26.79	0.362	9.19	–	–	PLB	PLB	PLBE	PLB
			21.4	31.85	0.437	11.1	–	–	PLB	PLB	PLB	PLB
			23.2	34.53	0.478	12.14	–	–	–	–	PLB	–
			24.1	35.86	0.5	12.7	–	–	–	–	PLB	–
5 1/2	5.5	139.7	14	20.83	0.244	6.2	PS	PS	–	–	–	–
			15.5	23.07	0.275	6.98	–	PSLB	–	–	–	–
			17	25.3	0.304	7.72	–	PSLB	PLB	PLB	PLBE	PLB
			20	29.76	0.361	9.17	–	–	PLB	PLB	PLBE	PLB
			23	34.23	0.415	10.54	–	–	PLB	PLB	PLBE	PLB
			26.8	39.88	0.5	12.7	–	–	–	–	–	–
			29.7	44.2	0.562	14.27	–	–	–	–	–	–
			32.6	48.51	0.625	15.88	–	–	–	–	–	–
			35.3	52.53	0.687	17.45	–	–	–	–	–	–
			38	56.55	0.75	19.05	–	–	–	–	–	–
			40.5	60.27	0.812	20.62	–	–	–	–	–	–
			43.1	64.14	0.875	22.22	–	–	–	–	–	–
6 5/8	6.625	168.28	20	29.76	0.288	7.32	PS	PSLB	–	–	–	–
			24	35.72	0.352	8.94	–	PSLB	PLB	PLB	PLBE	PLB
			28	41.67	0.417	10.59	–	–	PLB	PLB	PLBE	PLB
			32	47.62	0.475	12.06	–	–	PLB	PLB	PLBE	PLB
7	7	177.8	17	25.3	0.231	5.87	PS	–	–	–	–	–
			20	29.76	0.272	6.91	PS	PS	–	–	–	–
			23	34.23	0.317	8.05	–	PSLB	PLB	PLB	PLBE	–
			26	38.69	0.362	9.19	–	PSLB	PLB	PLB	PLBE	PLB
			29	43.16	0.408	10.36	–	–	PLB	PLB	PLBE	PLB
			32	47.62	0.453	11.51	–	–	PLB	PLB	PLBE	PLB
			35	52.09	0.498	12.65	–	–	PLB	PLB	PLBE	PLB
			38	56.55	0.54	13.72	–	–	PLB	PLB	PLBE	PLB
			42.7	63.54	0.625	15.88	–	–	–	–	–	–
			46.4	69.05	0.687	17.45	–	–	–	–	–	–
			50.1	74.56	0.75	19.05	–	–	–	–	–	–
			53.6	79.77	0.812	20.62	–	–	–	–	–	–
			57.1	84.97	0.875	22.22	–	–	–	–	–	–
7 5/8	7.625	193.68	24	35.72	0.3	7.62	PS	–	–	–	–	–
			26.4	39.29	0.328	8.33	–	PSLB	PLB	PLB	PLBE	PLB
			29.7	44.2	0.375	9.52	–	–	PLB	PLB	PLBE	PLB
			33.7	50.15	0.43	10.92	–	–	PLB	PLB	PLBE	PLB
			39	58.05	0.5	12.7	–	–	PLB	PLB	PLBE	PLB
			42.8	63.69	0.562	14.27	–	–	PLB	PLB	PLB	PLB
			45.3	67.41	0.595	15.11	–	–	PLB	PLB	PLB	PLB
			47.1	70.09	0.625	15.88	–	–	PLB	PLB	PLB	PLB
			51.2	76.19	0.687	17.45	–	–	–	–	–	–
			55.3	80.3	0.75	19.05	–	–	–	–	–	–
8 5/8	8.625	219.08	24	35.72	0.264	6.71	–	PS	–	–	–	–
			28	41.62	0.304	7.72	PS	–	–	–	–	–
			32	47.62	0.352	8.94	PS	PSLB	–	–	–	–
			36	53.57	0.4	10.16	–	PSLB	PLB	PLB	PLBE	PLB
			40	59.53	0.45	11.43	–	–	PLB	PLB	PLBE	PLB
			44	65.48	0.5	12.7	–	–	PLB	PLB	PLBE	PLB
			49	72.92	0.557	14.15	–	–	PLB	PLB	PLBE	PLB
9 5/8	9.625	244.48	32.3	48.07	0.312	7.92	PS	–	–	–	–	–
			36	53.57	0.352	8.94	PS	PSLB	–	–	–	–
			40	59.53	0.395	10.03	–	PSLB	PLB	PLB	PLBE	–
			43.5	64.73	0.435	11.05	–	–	PLB	PLB	PLBE	PLB
			47	69.94	0.472	11.99	–	–	PLB	PLB	PLBE	PLB
			53.5	79.62	0.545	13.84	–	–	PLB	PLB	PLBE	PLB
			58.4	86.91	0.595	15.11	–	–	PLB	PLB	PLB	PLB
			59.4	88.4	0.609	15.47	–	–	–	–	–	–
			64.9	96.58	0.672	17.07	–	–	–	–	–	–
			70.3	104.62	0.734	18.64	–	–	–	–	–	–
			75.6	112.5	0.797	20.24	–	–	–	–	–	–
10 3/4	10.75	273.05	32.75	48.74	0.279	7.09	PS	–	–	–	–	–
			40.5	60.27	0.35	8.89	PS	PSB	–	–	–	–
			15.5	67.71	0.4	10.16	–	PSB	–	–	–	–
			51	75.9	0.45	11.43	–	PSB	PSB	PSB	PSBE	PSB
			55.5	82.59	0.495	12.57	–	–	PSB	PSB	PSBE	PSB
			60.7	90.33	0.545	13.84	–	–	–	–	PSBE	PSB
			65.7	97.77	0.595	15.11	–	–	–	–	PSB	PSB
			73.2	108.93	0.672	17.07	–	–	–	–	–	–
			79.2	117.86	0.734	18.64	–	–	–	–	–	–
			85.3	126.94	0.797	20.24	–	–	–	–	–	–
11 3/4	11.75	298.45	42	62.5	0.333	8.46	PS	–	–	–	–	–
			47	69.94	0.375	20.24	–	–	–	–	–	–
			54	80.36	0.435	8.46	–	–	–	–	–	–
			60	89.29	0.489	9.53	–	–	–	–	–	–
			65	96.73	0.534	11.05	–	–	–	–	–	–
			71	105.66	0.582	14.42	–	–	–	–	–	–
13 3/8	13.375	339.73	48	71.43	0.33	8.38	PS	–	–	–	–	–
			54.5	81.1	0.38	9.65	–	PSB	–	–	–	–
			61	90.78	0.43	10.92	–	PSB	–	–	–	–
			68	101.19	0.48	12.19	–	PSB	PSB	PSB	PSB	PSB
			72	107.15	0.514	13.06	–	–	PSB	PSB	PSB	PSB
16	16	406.4	65	96.73	0.375	9.53	PS	–	–	–	–	–
			75	111.61	0.438	11.13	–	PSB	–	–	–	–
			84	125.01	0.495	12.57	–	PSB	–	–	–	–
			109	162.21	0.656	16.66	–	P	P	P	–	P
18 5/8	18.625	473.08	87.5	130.21	0.435	11.05	PS	PSB	–	–	–	–
20	20	508	94	139.89	0.438	11.13	PSL	PSLB	–	–	–	–
			106.5	158.49	0.5	12.7	–	PSLB	–	–	–	–
			133	197.93	0.635	16.13	–	PSLB	–	–	–	–
P——Plain；S——Short-thread；L——Long-thread；B——Buttress thread；E——Extreme thread

Oil Casing &Tubing (Octg) Production Process

Frequently Asked Questions

1. What specific grades and connection types do you provide for OCTG?

We offer a full range of API 5CT Casing & Tubing, including common grades like J55, K55, N80, and L80, available with standard connections (STC, LTC, BTC) or premium connections for specialized drilling environments.

2. How do you guarantee compliance with API 5CT standards?

Every pipe is manufactured to strict API 5L and API 5CT specifications and undergoes rigorous Internal Quality Control, including hydrostatic and non-destructive testing, to ensure reliability under downhole pressure.

3. Do you provide official certification for oilfield materials?

Yes, all products are delivered with a Mill Test Certificate (MTC) according to EN 10204 3.1, providing complete traceability of chemical composition and mechanical properties required for oil and gas projects.

4. How are the threads and pipe surfaces protected during international transit?

We use professional sea-worthy packaging, specifically applying heavy-duty thread protectors (plastic or metal) and anti-rust coatings to ensure the casing and tubing arrive at the wellsite in perfect condition

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Tags : API 5CT casing pipe , oil well casing , J55 casing , K55 casing , N80 casing , P110 casing

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