API 5B Casing Coupling for Petroleum Industry

Couplings are important components use to connect two sections of oil casing. They are internally machine with precise threads that match and tighten with the external upset end of the casing body, thereby joining individual sections of casing to form a sealed pipe string capable of withstanding complex underground loads and harsh environments. This provides support for the wellbore, prevents formation collapse, and isolates fluids from different formations.

Product Detail

Product Name:

API 5CT Casing Coupling for Petroleum Industry

Standard:

API 5CT / API 5B

Grade:

H40,J55,K55,N80-1,N80Q,R95,L80-1,L80-13Cr,C90,T95,C110,P110,Q125

Thickness:

3.5-60mm

Shape:

Round

Outer Diameter:

Ф114.3 – 406 mm

Place of Origin:

Inner Mongolia, China

Usage:

Structural Support; Wellbore Protection

Surface Treatment:

Hot Rolled

Tolerance:

OD: ±1%，not greater than ±3.18%

End:

Plain

End Protector:

HDPE crash cap or customized

length:

R1, R2, R3

Brand:

Baotou steel

Delivery Time:

Normally within 30-45 days and according to the quantity.

Chemical Component(API 5CT)

Grade	Type	C		Mn		Mo		Cr		Ni	Cu	P	S	Si
Grade	Type	Min	Max	Min	Max	Min	Max	Min	Max	Max	Max	Max	Max	Max
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
H40												0.030	0.030	一
J55												0.030	0.030	一
K55												0.030	0.030
N80	1											0.030	0.030	一
N80	Q											0.030	0.030	一
R95	一	一	0.45	一	1.90	一	一	一	一	一	一	0.030	0.030	0.45
L80	1	一	0.43	一	1.90	一	一	一	一	0.25	0.35	0.030	0.030	0.45
L80		一	0.15	0.30	0.60	0.90	1.10	8.00	10.0	0.50	0.25	0.020	0.010	1.00
L80	13Cr	0.15	0.22	0.25	1.00	一	一	12.0	14.0	0.50	0.25	0.020	0.010	1.00
C90	1	一	0.35	—	1.20	0.25	0.85	—	1.50	0.99	一	0.020	0.010	一
T95	1	一	0.35	一	1.20	025	0.85	0.40	1.50	0.99	一	0.020	0.010	一
C110	一	一	0.35	一	1.20	0.25	1.00	0.40	1.50	0.99	一	0.020	0.005	一
P110												0.030	0.030	一
Q125	1	一	0.35		1.35	一	0.85	一	1.50	0.99	一	0.020	0.010	一

Mechanical Property(API 5CT)

Grade	Type	Total under load Elongation %	Yield strength megapascal		Tensile strength megapascal	Hardness a, C Maximum			Specified OD mm	Allowable hardness Variation
Grade	Type	Total under load Elongation %	Min	Max	Min	HRC	HBW		Specified OD mm	HRC
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	–	–		–	–
L80	1	0.5	552	655	655	23.0	241		–	–
L80	3Cr	0.5	552	655	655	23.0	241		–	–
L80	9Cr	0.5	552	655	655	23.0	241		–	–
L80	13Cr	0.5	552	655	655	23.0	241		–	–
C90	–	0.5	621	724	689	25.4		255	≤12.70	3.0
									12.71 to 19.04	4.0
									19.05 to 25.39	5.0
									≥25.40	6.0
T95	–	0.5	655	758	724	25.4		255	≤12.70	3.0
									12.71 to 19.04	4.0
									19.05 to 25.39	5.0
									≥25.40	6.0
C110	–	0.7	758	828	793	29		279	≤12.70	3.0
									12.71 to 19.04	4.0
									19.05o to 25.39	5.0
									≥25.40	6.0
P110	–	0.6	758	965	862	–		–	–	–
Q125	–	0.65	862	1034	931	b		–	≤12.70	3.0
									12.71 to 19.04	4.0
									≥19.05	5.0

Advantages:

The product utilizes Baogang’s proprietary “rare earth steel” metallurgical technology. The incorporation of rare earth elements significantly refines the steel’s grain structure, substantially enhancing the coupling’s comprehensive mechanical properties, corrosion resistance, and fatigue endurance. It demonstrates exceptional performance particularly in acidic corrosive environments containing H₂S, CO₂, and chloride ions.

Leveraging advanced CNC and fully automated threading production lines, micron-level precision is guaranteed for every thread. Parameters including thread profile, taper, and pitch are perfectly matched, achieving 100% connection efficiency and exceptional gas sealing performance.

Products cover all standard API steel grades and high-value-added grades (e.g., C90, T95, Q125), offering multiple thread types including BTC, STC, and LTC.

End-to-end quality tracking is implemented from raw material intake to finished product shipment. Each batch undergoes UT, MT, hardness testing, full-dimension inspection, and pressure testing to ensure zero-defect delivery.