API H40 casing pipe is manufactured in accordance with API Spec 5CT, the primary standard for casing and tubing used in oil and gas wells.
This standard defines:
Material composition requirements
Mechanical properties
Dimensional tolerances
Inspection and testing procedures
H40 casing is typically used in low to medium pressure well environments.
The chemical composition of API H40 casing pipe is controlled to ensure a balance between strength, toughness, and weldability.
|
Element |
Content (%) |
|
Carbon (C) |
≤ 0.22 |
|
Manganese (Mn) |
0.30 – 1.20 |
|
Phosphorus (P) |
≤ 0.030 |
|
Sulfur (S) |
≤ 0.030 |
|
Silicon (Si) |
0.10 – 0.35 |
Low P and S content improves ductility and reduces brittleness.
API H40 casing pipe mechanical properties are designed to withstand drilling and production loads:
Tensile Strength: ≥ 552 MPa (80 ksi)
Yield Strength: ≥ 276 MPa (40 ksi)
Elongation: ≥ 20% (within 2 inches)
These values ensure structural integrity and deformation resistance under field conditions.
To guarantee performance and interchangeability, API 5CT casing pipe tolerances include:
Outer Diameter (OD): ±1%
Wall Thickness (WT): ±12.5%
Weight: ±10% per unit length
Precision tolerances are critical for thread connection sealing and well safety.
Cost-effective casing solution
Moderate strength with good ductility
Easy processing and welding
Suitable for non-critical well sections
|
DN |
O. D. |
Weight |
W. T. |
End Machining Form |
|||
|
Steel Grade |
|||||||
|
in |
mm |
lb/ft |
kg/m |
in |
mm |
H40 |
|
|
4 1/2 |
4.500 |
114.3 |
9.5 |
14.14 |
0.205 |
5.21 |
PS |
|
10.5 |
15.63 |
0.224 |
5.69 |
– |
|||
|
11.6 |
17.26 |
0.250 |
6.35 |
– |
|||
|
13.5 |
20.09 |
0.290 |
7.37 |
– |
|||
|
15.1 |
22.47 |
0.337 |
9.56 |
– |
|||
|
5 |
5.000 |
127 |
11.5 |
17.11 |
0.220 |
5.59 |
– |
|
13 |
19.35 |
0.253 |
6.43 |
– |
|||
|
15 |
22.32 |
0.296 |
7.52 |
– |
|||
|
18 |
26.79 |
0.362 |
9.19 |
– |
|||
|
21.4 |
31.85 |
0.437 |
11.1 |
– |
|||
|
23.2 |
34.53 |
0.478 |
12.14 |
– |
|||
|
24.1 |
35.86 |
0.500 |
12.7 |
– |
|||
|
5 1/2 |
5.500 |
139.7 |
14 |
20.83 |
0.244 |
6.2 |
PS |
|
15.5 |
23.07 |
0.275 |
6.98 |
– |
|||
|
17 |
25.3 |
0.304 |
7.72 |
– |
|||
|
20 |
29.76 |
0.361 |
9.17 |
– |
|||
|
23 |
34.23 |
0.415 |
10.54 |
– |
|||
|
26.8 |
39.88 |
0.500 |
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 |
0.750 |
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 |
|
24 |
35.72 |
0.352 |
8.94 |
– |
|||
|
28 |
41.67 |
0.417 |
10.59 |
– |
|||
|
32 |
47.62 |
0.475 |
12.06 |
– |
|||
|
7 |
7.000 |
177.8 |
17 |
25.3 |
0.231 |
5.87 |
PS |
|
20 |
29.76 |
0.272 |
6.91 |
PS |
|||
|
23 |
34.23 |
0.317 |
8.05 |
– |
|||
|
26 |
38.69 |
0.362 |
9.19 |
– |
|||
|
29 |
43.16 |
0.408 |
10.36 |
– |
|||
|
32 |
47.62 |
0.453 |
11.51 |
– |
|||
|
35 |
52.09 |
0.498 |
12.65 |
– |
|||
|
38 |
56.55 |
0.540 |
13.72 |
– |
|||
|
42.7 |
63.54 |
0.625 |
15.88 |
– |
|||
|
46.4 |
69.05 |
0.687 |
17.45 |
– |
|||
|
50.1 |
74.56 |
0.750 |
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 |
0.300 |
7.62 |
PS |
|
26.4 |
39.29 |
0.328 |
8.33 |
– |
|||
|
29.7 |
44.2 |
0.375 |
9.52 |
– |
|||
|
33.7 |
50.15 |
0.430 |
10.92 |
– |
|||
|
39 |
58.05 |
0.500 |
12.7 |
– |
|||
|
42.8 |
63.69 |
0.562 |
14.27 |
– |
|||
|
45.3 |
67.41 |
0.595 |
15.11 |
– |
|||
|
47.1 |
70.09 |
0.625 |
15.88 |
– |
|||
|
51.2 |
76.19 |
0.687 |
17.45 |
– |
|||
|
55.3 |
80.3 |
0.750 |
19.05 |
– |
|||
|
8 5/8 |
8.625 |
219.08 |
24 |
35.72 |
0.264 |
6.71 |
– |
|
28 |
41.62 |
0.304 |
7.72 |
PS |
|||
|
32 |
47.62 |
0.352 |
8.94 |
PS |
|||
|
36 |
53.57 |
0.400 |
10.16 |
– |
|||
|
40 |
59.53 |
0.450 |
11.43 |
– |
|||
|
44 |
65.48 |
0.500 |
12.7 |
– |
|||
|
49 |
72.92 |
0.557 |
14.15 |
– |
|||
|
9 5/8 |
9.625 |
244.48 |
32.3 |
48.07 |
0.312 |
7.92 |
PS |
|
36 |
53.57 |
0.352 |
8.94 |
PS |
|||
|
40 |
59.53 |
0.395 |
10.03 |
– |
|||
|
43.5 |
64.73 |
0.435 |
11.05 |
– |
|||
|
47 |
69.94 |
0.472 |
11.99 |
– |
|||
|
53.5 |
79.62 |
0.545 |
13.84 |
– |
|||
|
58.4 |
86.91 |
0.595 |
15.11 |
– |
|||
|
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 |
10.750 |
273.05 |
32.75 |
48.74 |
0.279 |
7.09 |
PS |
|
40.5 |
60.27 |
0.350 |
8.89 |
PS |
|||
|
15.5 |
67.71 |
0.400 |
10.16 |
– |
|||
|
51 |
75.9 |
0.450 |
11.43 |
– |
|||
|
55.5 |
82.59 |
0.495 |
12.57 |
– |
|||
|
60.7 |
90.33 |
0.545 |
13.84 |
– |
|||
|
65.7 |
97.77 |
0.595 |
15.11 |
– |
|||
|
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 |
11.750 |
|
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 |
0.330 |
8.38 |
PS |
|
54.5 |
81.1 |
0.380 |
9.65 |
– |
|||
|
61 |
90.78 |
0.430 |
10.92 |
– |
|||
|
68 |
101.19 |
0.480 |
12.19 |
– |
|||
|
72 |
107.15 |
0.514 |
13.06 |
– |
|||
|
16 |
16.000 |
406.4 |
65 |
96.73 |
0.375 |
9.53 |
PS |
|
75 |
111.61 |
0.438 |
11.13 |
– |
|||
|
84 |
125.01 |
0.495 |
12.57 |
– |
|||
|
109 |
162.21 |
0.656 |
16.66 |
– |
|||
|
18 5/8 |
18.625 |
473.08 |
87.5 |
130.21 |
0.435 |
11.05 |
PS |
|
20 |
20.000 |
508 |
94 |
139.89 |
0.438 |
11.13 |
PSL |
|
106.5 |
158.49 |
0.500 |
12.7 |
– |
|||
|
133 |
197.93 |
0.635 |
16.13 |
– |
|||
Common applications of API H40 casing pipe include:
Surface casing
Conductor casing
Shallow oil and gas wells
Low-pressure formations
What is API H40 casing pipe used for?
API H40 casing pipe is mainly used in shallow wells and low-pressure environments, especially for surface casing.
Is API H40 casing pipe suitable for deep wells?
No. API H40 is a low-strength casing grade, not suitable for deep or high-pressure wells.
Which standard defines API H40 casing pipe?
It is defined by API Spec 5CT, covering material, dimensions, and testing requirements.
What are the main advantages of API H40 casing pipe?
Lower cost
Good ductility
Adequate performance for non-critical applications
Why are API 5CT tolerances important for casing pipe?
They ensure proper fit, connection integrity, and safe operation in oilfield conditions.
API H40 casing pipe is an entry-level grade under API 5CT
Provides balanced mechanical performance and cost efficiency
Ideal for low-risk, shallow well applications
Proper selection of casing grade is essential to optimize cost while maintaining well integrity.
