API 5CT Casing and Tubing

The API 5CT standard’s main purpose is to ensure the quality and reliability of oil pipelines, wellheads, and oilfield equipment.

In addition to casing and tubing, it also includes pup joints, coupling blanks, coupling materials and accessory materials. We offer a range of options to suit your specific needs across three product specification levels (PSL-1, PSL-2 and PSL-3).

PSL-1 is the basis of this standard and PSL-3 is robust.

At UNIASEN, we offer premium quality API 5CT casing and tubing designed to meet the stringent requirements of the oil and gas industry.


Steel Grade: H40, N80-1, J55, L80Cr, K55, C90-1, N80, T95-1, N80Q, C110, R95, P110, L80, Q125

Procedure: ERW, SMLS

Dimensions: Casing Pipe 114.3 – 508mm (4 1/2”- 20″); Tubing Pipe 26.67 – 114.3mm (1.05” -4 1/2”)

Thickness: 5.21mm – 22.22mm

Unit Length: Casing Pipe 4.88 – 14.63 mtrs, Tubing Pipe 6.10 – 12.80 mtrs

Surface Coating: Varnishing, Black Varnishing

End Type: Plain end, Short Round Thread, Long Round Thread, Buttress Thread, Extreme-line.

Plain end, Non-upset Threaded and Coupled, External upset Threaded and couple,Intergral

JointJoint Method: Coupling

Further Processing: Threading

API 5CT Casing and Tubing-UNIASEN


UNIASEN’s API 5CT Casing and Tubing are available in a multitude of dimensions that adhere to international standards. Our dimension table includes precise details on sizes, masses, and wall thicknesses, providing you with a clear understanding of what you are purchasing. With our extensive selection, you can find the perfect fit for your project, knowing that each product is engineered to meet the highest industry standards. Trust in our expertise, and let us provide the perfect dimensions for your success.

API Casing List-Thickness
4 1/2114.35.215.696.357.378.56
5 1/2139.76.206.987.729.1710.5412.7014.2715.8817.4519.0520.6222.22
6 5/8168.37.328.9410.5912.06
7 5/8193.77.628.339.5210.9212.7014.2715.1115.8817.4519.05
7 3/4196.915.11
8 5/8219.16.717.728.9410.1611.4312.7014.15
9 5/8244.57.928.9410.0311.0511.9913.8415.1115.4717.0718.6420.24
10 3/4273.17.098.8910.1611.4312.5713.8415.1117.0718.6420.24
11 3/4298.58.469.5311.0512.4213.5614.78
13 3/8339.78.389.6510.9212.1913.06
18 5/847311.05

Chemical Requirement

We at UNIASEN understand the importance of chemical composition in steel pipes. Our API 5CT Casing and Tubing are manufactured with a specific chemical requirement that ensures durability, corrosion resistance, and high performance. By choosing our products, you are investing in materials that have been meticulously crafted to meet stringent industry standards. Our commitment to quality ensures that you receive products that not only meet but exceed your expectations.

Chemical Composition, Mass Fraction (%)
123          4456789101112131415
H400.030     0.45
J550.030     0.45
K550.030     0.45
N8010.0300.030     0.45
N80Q0.0300.030     0.45
R950.45c1.90.0300.030     0.450.45
L8010.43a1.90.25     0.350.350.0300.030     0.450.45
L809Cr0.150.300.600.901.108.0010.00.50     0.451.00
L8013Cr0.     0.451.00
C9010.351.200.25b0.851.500.990.0200.030     0.45
T9510.351.200.25b0.850.401.500.990.0200.030     0.45
C1100.351.     0.45
NOTE   Elements shown shall be repored in product analysis.
a   The carbon content for L80 may be increased up to 0.50 % maximum if the product is oil-quenched or polymer-quenched.
b   The molybdenum content for Grade C90 Type 1 has no minimum tolerance if the wall thickness 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 wall thickness is less than 17.78 mm.
d   For EW Grade P110, the phosphorus content shall be 0.020% maximum and the sulfur content 0.010% maximum.

Chemical Composition for PSL 2 Pipe with t ≤ 25.0 mm (0.984 in.)

Steel Grade
(Steel Name)
   Mass Fraction, Based on Heat and Product Analyses
% max
Equivalent a
% max
Seamless and Welded Pipe
L245R or BR0.240.401.200.0250.015cc0.04e,l0.430.25
L290R or X42R0.240.401.200.0250.0150.060.050.04e,l0.430.25
L245N or BN0.240.401.200.0250.015cc0.04e,l0.430.25
L290N or X42N0.240.401.200.0250.0150.060.050.04e,l0.430.25
L320N or X46N0.240.401.400.0250.0150.070.050.04d,e,l0.430.25
L360N or X52N0.240.451.400.0250.0150.100.050.04d,e,l0.430.25
L390N or X56N0.240.451.400.0250.0150.10 f0.050.04d,e,l0.430.25
L415N or X60N0.24 f0.45 f1.40 f0.0250.0150.10 f0.05 f0.04 fg,h,lAs agreed
L245Q or BQ0.180.451.400.0250.0150.050.050.04e,l0.430.25
L290Q or X42Q0.180.451.400.0250.0150.050.050.04e,l0.430.25
L320Q or X46Q0.180.451.400.0250.0150.050.050.04e,l0.430.25
L360Q or X52Q0.180.451.500.0250.0150.050.050.04e,l0.430.25
L390Q or X56Q0.180.451.500.0250.0150.070.050.04d,e,l0.430.25
L415Q or X60Q0.18 f0.45 f1.70 f0.0250.015gggh,l0.430.25
L450Q or X65Q0.18 f0.45 f1.70 f0.0250.015gggh,l0.430.25
L485Q or X70Q0.18 f0.45 f1.80 f0.0250.015gggh,l0.430.25
L555Q or X80Q0.18 f0.45 f1.90 f0.0250.015gggi,jAs agreed
L625Q or X90Q0.16 f0.45 f1.900.020.010gggj,kAs agreed
L690Q or X100Q0.16 f0.45 f1.900.020.010gggj,kAs agreed
Welded Pipe
L245M or BM0.220.451.200.0250.0150.050.050.04e,l0.430.25
L290M or X42M0.220.451.300.0250.0150.050.050.04e,l0.430.25
L320M or X46M0.220.451.300.0250.0150.050.050.04e,l0.430.25
L360M or X52M0.220.451.400.0250.015ddde,l0.430.25
L390M or X56M0.220.451.400.0250.015ddde,l0.430.25
L415M or X60M0.12 f0.45 f1.60 f0.0250.015gggh,l0.430.25
L450M or X65M0.12 f0.45 f1.60 f0.0250.015gggh,l0.430.25
L485M or X70M0.12 f0.45 f1.70 f0.0250.015gggh,l0.430.25
L555M or X80M0.12 f0.45 f1.85 f0.0250.015gggi,l0.43 f0.25
L625M or X90M0.100.55 f2.10 f0.020.010gggi,l0.25
L690M or X100M0.100.55 f2.10 f0.020.010gggi,j0.25
L830M or X120M0.100.55 f2.10 f0.020.010gggi,j0.25
a    Based on product analysis, for seamless pipe with t > 20.0 mm (0.787 in.), the CE limits shall be as agreed; the CEIIW limits
apply if C > 0.12 % and the CEPcm limits apply if C ≤ 0.12 %.
b    For each reduction of 0.01 % below the specified maximum for C, an increase of 0.05 % above the specified maximum for
Mn is  permissible, up to a maximum of 1.65 % for grades ≥ L245 or B, but ≤ L360 or X52; up to a maximum of 1.75 % for
grades > L360 or X52, but < L485 or X70; up to a maximum of 2.00 % for grades ≥ L485 or X70, but ≤ L555 or X80; and up to a
maximum of 2.20 % for grades > L555 or X80.
c    Unless otherwise agreed, Nb + V ≤ 0.06 %.
d    Nb + V + Ti ≤ 0.15 %.
e    Unless otherwise agreed, Cu ≤ 0.50 %; Ni ≤ 0.30 %; Cr ≤ 0.30 % and Mo ≤ 0.15 %.
f     Unless otherwise agreed.
g    Unless otherwise agreed, Nb + V + Ti ≤ 0.15 %.
h    Unless otherwise agreed, Cu ≤ 0.50 %; Ni ≤ 0.50 %; Cr ≤ 0.50 % and Mo ≤ 0.50 %.
i     Unless otherwise agreed, Cu ≤ 0.50 %; Ni ≤ 1.00 %; Cr ≤ 0.50 % and Mo ≤ 0.50 %.
j      B ≤ 0.004 %.
k     Unless otherwise agreed, Cu ≤ 0.50 %; Ni ≤ 1.00 %; Cr ≤ 0.55 % and Mo ≤ 0.80 %.
l      For PSL 2 pipe grades except those grades to which footnote j) already applies, the following applies: unless otherwise
agreed no intentional addition of B is permitted and residual B ≤ 0.001 %.

Mechanical Requirement

Mechanical integrity is at the core of our API 5CT Casing and Tubing. UNIASEN’s products are engineered to meet specific mechanical requirements, providing robustness, resilience, and long-lasting performance. Whether it’s tensile strength, yield strength, or hardness, our products are designed to withstand the challenges of the most demanding environments. Choose UNIASEN, and benefit from steel pipes that perform when it matters most.

Tensile and Hardness Requirements
GradeTypeTotal Elongation Under LoadYield strength MPaTensile strength
Hardness a,c
Specified Wall ThicknessAllowable
Variation b
12.71 to 19.04
19.05 to 25.39
12.71 to 19.04
19.05 to 25.39
12.71 to 19.04
19.05 to 25.39
12.71 to 19.04
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 restricted as a manufacturing control in accordance with 7.8 and 7.9.
c   For through-wall hardness tests of Grades L80(all types), C90, T98 and C110, the requirements stated in HRC scale are for maximum mean hardness number.

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