P110 Casing Pipe: Complete Guide to API 5CT Specifications
What Is P110 Casing Pipe?
P110 is a high-strength carbon steel casing grade defined under API 5CT, with a yield strength of 110,000–140,000 psi and a minimum tensile strength of 125,000 psi. Through quenching and tempering, API 5CT P110 casing achieves a uniform tempered microstructure that delivers excellent strength and consistent hardness across the pipe wall. P110 casing pipe is available in sizes from 4½″ to 20″, covering surface, intermediate, and production strings in deep and ultra-deep wells where high collapse and burst resistance are critical. Compared to lower grades such as N80 or L80, grade P110 casing offers significantly higher load-bearing capacity, making it the preferred choice for high-pressure gas wells and demanding directional drilling programs. All products are manufactured and tested in accordance with API 5CT / ISO 11960 specifications.
- Applicable Product: Casing & Tubing 4½″–20″
- Thread Types: STC / LTC / BTC, Premium Connections
- Available Lengths: R1 / R2 / R3
- Service Environment: High-Pressure Deep Wells, API 5CT / ISO 11960 Compliant
Chemical Composition of P110 Casing Pipe
| Grade | C | Mn | Mo | Cr | Ni max. | Cu max. | P max. | S max. | Si |
| API 5CT P110 | — | — | — | — | — | — | ≤ 0.030% | ≤ 0.030% | — |
| API 5CT P110 EW / ERW | — | — | — | — | — | — | ≤ 0.020% | ≤ 0.010% | — |
Note: API 5CT mainly restricts P and S in the standard chemical composition of P110. Other elements are usually implemented according to the steel mill’s smelting design and are reported in the MTC/MTR material certificate.
Mechanical Properties of P110 Casing Pipe
| Grade | Yield Strength min. | Yield Strength max. | Tensile Strength min. | Hardness max. | Heat Treatment |
| API 5CT P110 | 758 MPa / 110,000 psi | 965 MPa / 140,000 psi | 862 MPa / 125,000 psi | No API specified limit | Quenched & Tempered |
Test requirements of P110 Casing Pipe
| Steel Grade | Mandatory Tests | Supplementary Tests | NDT | Corrosion Test | Key Control Requirements |
| P110 | Chemical analysis Tensile, Hardness Hydrostatic pressure | Metallographic examination | UT | None | Quenched and tempered structure |
API 5CT Grade P110
P110 Casing Pipe Specifications
High-strength P110 casing pipe engineered for deep, high-pressure oil and gas wells. Minimum yield strength 110 ksi (758 MPa) per API 5CT, available in seamless and ERW with BTC, LTC, STC, and premium connections.
P110 Casing Sizes and Dimensions
Below are the most commonly ordered P110 casing configurations. Dimensions per API 5CT / ISO 11960. Contact us for additional sizes or custom requirements.
5-1/2″ P110 Casing
17# – 23# | Wall: 7.72 – 10.54 mm
7″ P110 Casing
23# – 38# | Wall: 8.05 – 13.72 mm
9-5/8″ P110 Casing
53.5# | Wall: 13.84 mm | BTC ends R2
13-3/8″ P110 Casing
54.5# – 72# | Wall: 9.65 – 13.06 mm
7-5/8″ P110 Casing
33.7# – 42.8# | Wall: 10.92 – 14.27 mm
4-1/2″ P110 Casing
11.6# – 15.1# | Wall: 6.35 – 8.56 mm
API 5CT P110 Specifications Chart
Select your required casing size below. Check one or more rows, then click Request Quote to email your inquiry directly to our sales team.
| OD (in) | OD (mm) | Weight (lb/ft) | Wall Thickness (in) | Wall Thickness (mm) | ID (in) | Drift Dia. (in) |
|---|
Industry Applications
Applications of P110 Casing Pipe
API 5CT P110 is the standard high-strength grade for intermediate and production casing in deep oil and gas wells, delivering the collapse and burst resistance that lower grades cannot match.
Min. Yield Strength
110 ksi
758 MPa — for wells where N80 or L80 fall short on pressure containment
P110 Casing Pipe Length
R3 Preferred
10.36–14.63 m (34–48 ft) — fewer joints, fewer leak paths, faster running
OD Range
4-1/2″ – 20″
Available with BTC, LTC, STC, and premium connections in R1, R2, R3
Deep Well and High-Pressure Applications
API 5CT P110 deep well casing pipe is specifically designed for environments where standard grades like N80 or L80 cannot provide adequate pressure containment. Below are the primary application scenarios.
Deep Production Wells
Used as production casing at depths exceeding 3,000 m (10,000 ft) where formation pressures demand high collapse and burst ratings beyond N80 capability.
High-Pressure Gas Wells
P110's superior burst resistance makes it ideal for gas wells with high shut-in pressures, providing reliable zonal isolation under extreme internal pressure loads.
HPHT Environments
In high-pressure high-temperature wells (150°C+), P110 provides the mechanical strength margin required after applying thermal de-rating factors to yield strength.
Intermediate Casing Strings
Installed between surface casing and production casing to isolate unstable formations, abnormal pressure zones, and prevent wellbore collapse at critical depths.
Grade Selection by Well Depth — P110 Is the Standard for Deep, High-Pressure Wells
Planning a deep well project? Get expert guidance on API 5CT P110 deep well casing pipe sizing, wall thickness selection, and connection recommendations.
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P110 Casing and Tubing
In a completed well, casing and tubing serve different but complementary roles. Casing is the larger-diameter pipe cemented into the wellbore to provide structural support and zonal isolation. Tubing is the smaller pipe suspended inside the casing through which oil or gas actually flows to the surface.
P110 grade is available for both. P110 casing (typically 4-1/2″ to 20″ OD) handles external collapse and internal burst loads, while P110 tubing (typically 2-3/8″ to 4-1/2″ OD with EUE or NU ends) handles production pressure and corrosion exposure.
Need both casing and tubing? We supply matched P110 strings.
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Wellbore Cross-Section — Casing vs. Tubing Configuration
P110 is a steel grade, not one fixed pipe size. API 5CT P110 casing is commonly supplied in casing outside diameters from 4-1/2 in to 20 in or 114.3 mm to 508.0 mm.
P ≤ 0.030% and S ≤ 0.030%.
For electric-welded P110 casing,P ≤ 0.020% and S ≤ 0.010%.
API 5CT P110 does not specify a fixed maximum HRC hardness
P110 casing is installed in the wellbore to support the well wall, isolate formations, protect the well structure, and withstand external pressure. It usually has a larger outside diameter and is cemented in place.
P110 tubing is installed inside the casing and is mainly used to transport oil, gas, or water from the reservoir to the surface.
Compared with casing, tubing has a smaller diameter and is more closely related to production flow and workover operations.
API 5CT P110 means a casing or tubing product manufactured under API Specification 5CT,P110 is the API grade designation; “110” indicates a minimum yield strength of 110,000 psi, equal to about 758 MPa.
