Seamless OCTG Pipe - API 5CT Certified Manufacturer | SteelPro Group

Kuaima Steel Co., Ltd.

Verified Custom manufacturer 7yrs

Technical Specifications of Seamless OCTG Pipe

Property	Parameter	Description
Product Name	Seamless OCTG Pipe	Oil Country Tubular Goods including casing, tubing, and drill pipe for oil & gas wells
Material Grade	J55 / K55 / N80 / L80 / P110 / Q125	Per API 5CT specification; equivalent to ISO 11960
Standard Compliance	API 5CT / ISO 11960	American Petroleum Institute & international oilfield tubular standards
Manufacturing Process	Hot-Rolled Seamless	Produced by piercing solid round billets; no weld seam for superior pressure integrity
Chemical Composition (J55)	C ≤0.34%, Mn ≤1.35%, P ≤0.020%, S ≤0.020%, Si ≤0.35%	Controlled chemistry per API 5CT PSL-2 requirements
Chemical Composition (N80-1)	C ≤0.34%, Mn ≤1.35%, P ≤0.020%, S ≤0.015%, Cr ≤0.15%, Mo ≤0.15%	Quenched and tempered grade with tighter sulfur control
Tensile Strength	517–862 MPa (J55) / 689–862 MPa (N80) / 862–1034 MPa (P110)	Minimum to maximum UTS per API 5CT Table C.6
Yield Strength	379–552 MPa (J55) / 552–758 MPa (N80) / 758–965 MPa (P110)	Minimum to maximum yield per API 5CT requirements
Elongation	≥19.5% (J55) / ≥14.0% (N80) / ≥12.0% (P110)	Minimum elongation on 2-inch gauge length specimen
Outer Diameter Range	2-3/8″ – 20″ (60.3 – 508.0 mm)	Covers tubing (2-3/8″–4-1/2″) and casing (4-1/2″–20″) sizes
Wall Thickness	4.24 – 16.13 mm	Various weight classes available per API 5CT dimensional tables
Length	R1 (4.88–7.62 m) / R2 (7.62–10.36 m) / R3 (10.36–14.63 m)	Range lengths as defined by API 5CT
Thread Connection	STC / LTC / BTC / Premium (VAM, etc.)	Short/Long/Buttress thread coupling; premium connections on request
Surface Finish	Varnished / Oiled / Black Phosphated	Internal and external anti-corrosion coating; thread protectors included
Application	Oil & Gas Drilling, Well Casing, Production Tubing, Sour Service (L80/C95)	Upstream exploration and production in onshore/offshore environments
Certification	API 5CT Monogram, ISO 11960, ISO 9001, NACE MR0175 (sour service grades)	Third-party inspection available (SGS, BV, TÜV, Lloyd's)
Packaging	Bundled with steel strips, thread protectors, beveled or plain ends	Seaworthy packing; marking per API 5CT Clause 11
MOQ	20 Metric Tons	Smaller trial orders negotiable; stock items available for common sizes

Seamless OCTG Pipe - API 5CT Certified Manufacturer | SteelPro Group

Seamless OCTG pipe serves as the backbone of modern oil and gas well construction, engineered to withstand extreme downhole pressures, corrosive environments, and high-temperature conditions encountered during drilling and production operations. As an API 5CT certified manufacturer, SteelPro Group delivers premium grade seamless OCTG tubing and casing that meets the rigorous demands of onshore and offshore exploration projects worldwide. Our vertically integrated production facility ensures full traceability from raw billet to finished product, providing operators and distributors with reliable, cost-effective tubular solutions backed by comprehensive quality documentation.

What Is Seamless OCTG Pipe?

Seamless OCTG (Oil Country Tubular Goods) pipe refers to hot-rolled or cold-drawn tubular steel products manufactured without a welded seam, specifically designed for petroleum and natural gas well applications. These products encompass three primary categories: casing, which lines the wellbore to prevent collapse and isolate geological formations; tubing, which conveys hydrocarbons from the production zone to the surface; and drill pipe, which transmits rotational force and drilling fluid during well construction. The seamless manufacturing process eliminates weld-related weaknesses, delivering superior pressure integrity and uniform mechanical properties critical for downhole service where failure carries severe safety and environmental consequences.

Seamless OCTG Pipe Technical Specifications

SteelPro Group manufactures seamless OCTG pipe in full compliance with API 5CT / ISO 11960 standards, covering a comprehensive range of grades, sizes, and connection types to suit diverse well conditions.

Parameter	Specification Range
Applicable Standards	API 5CT (PSL1 & PSL2), ISO 11960, ASTM A519
Steel Grades	J55, K55, N80-1, N80-Q, L80, C90, T95, P110, Q125
Outside Diameter	2-3/8″ (60.3 mm) to 20″ (508 mm)
Wall Thickness	4.24 mm to 16.13 mm
Length Range	R1 (4.88–7.62 m), R2 (7.62–10.36 m), R3 (10.36–14.63 m)
Yield Strength (P110)	758 MPa minimum to 965 MPa maximum per API 5CT
Tensile Strength (P110)	862 MPa minimum
Connection Types	STC, LTC, BTC, Premium (VAM-equivalent, gas-tight threads)
End Finish	Threaded & coupled, plain end, or beveled end
Surface Treatment	Phosphating, varnish coating, or bare with rust preventive oil
Testing	Hydrostatic test, full-body UT/EMI, drift test, hardness test (HRC ≤ 22 for L80)

For sour service applications (NACE MR0175 / ISO 15156 compliance), we supply L80, C90, and T95 grades with controlled hardness not exceeding HRC 22, HRC 25.4, and HRC 25.4 respectively, along with mandatory SSC testing to ensure hydrogen sulfide resistance in corrosive well environments.

Key Advantages of SteelPro Seamless OCTG Pipe

Superior Pressure Integrity: The seamless manufacturing process—piercing a solid round billet on a rotary mill followed by elongation and sizing—produces a homogeneous grain structure free from weld-line vulnerabilities. This delivers burst and collapse ratings that consistently meet or exceed API 5CT minimum requirements.

Full API 5CT PSL2 Compliance: Our PSL2 production protocol incorporates mandatory chemical composition verification per heat, product analysis on each lot, full-length non-destructive examination (ultrasonic and electromagnetic inspection), and enhanced traceability—ensuring every joint of seamless OCTG pipe leaving our facility meets the most stringent product specification level.

Seamless OCTG pipe manufacturer

Comprehensive Thread Solutions: Beyond standard API connections (STC, LTC, BTC), SteelPro offers premium proprietary threads featuring metal-to-metal seals and torque shoulders, engineered for gas-tight performance at pressures exceeding 10,000 psi and temperatures up to 250°C in high-pressure/high-temperature (HPHT) wells.

Mill-Direct Cost Efficiency: By sourcing directly from our integrated steel mill, customers eliminate intermediary markups while benefiting from flexible production scheduling, customized stenciling, and consolidated shipments that reduce total landed cost per metric ton.

Frequently Asked Questions

What is the MOQ for seamless OCTG pipe?

Our standard minimum order quantity is 20 metric tons per grade and size combination. For project-based orders involving multiple specifications, we offer flexible MOQ arrangements—contact our sales team for a tailored solution.

Do you provide material test certificates?

Yes. Every shipment includes EN 10204 Type 3.1 mill test certificates documenting chemical composition, mechanical properties (yield, tensile, elongation, hardness), hydrostatic test results, and NDE inspection records. Third-party inspection by SGS, Bureau Veritas, or TÜV is available upon request.

What is the typical delivery time?

Standard stock items ship within 7–15 business days. Custom orders—including non-standard grades, premium connections, or special coatings—typically require 30–45 days from order confirmation, depending on quantity and specification complexity.

Can you cut to custom sizes?

Absolutely. We provide precision cutting to customer-specified lengths within the R1, R2, and R3 ranges, as well as non-standard lengths for specialized applications. All cut pieces undergo drift testing and end preparation per your project requirements.

Seamless OCTG pipe supplier

Get a Competitive Quote for Seamless OCTG Pipe

Whether you are sourcing casing for a deep sour gas well or tubing for a high-volume production string, SteelPro Group delivers API 5CT certified seamless OCTG pipe at mill-direct rates with reliable lead times. Share your project specifications—including grade, size, connection type, and required quantity—and our technical sales team will respond within 24 hours with a detailed quotation, stock availability, and recommended logistics solutions tailored to your destination port.

Seamless OCTG pipe factory

Ratings & Reviews

5.0

Very satisfied

Based on 8 reviews for verified purchases

Supplier service

5.0

On-time shipment

5.0

Supplier service

5.0

Helen Bancroft

United Kingdom

verified purchases

2025-01-31

Quality Fine, Initial Shipping Label Mix-Up Resolved Quickly
Ordered 55 MT of L80 seamless casing, 7-5/8" OD with BTC connections for an Irish Sea project. The pipe quality itself was good—hardness at HRC 20.5, hydrostatic tested, full UT inspection passed. However, two bundles had incorrect shipping labels showing wrong heat numbers, which caused confusion during our receiving inspection. Contacted SteelPro and they provided corrected documentation with full traceability within 48 hours, confirmed by cross-referencing stencil markings on the pipes. Issue resolved satisfactorily, but tighter QC on labeling would prevent this in future.

David Crawford

United States

verified purchases

2025-02-23

Competitive Pricing on J55 and N80-1 Casing Mix
We stock OCTG for regional operators and ordered a mixed lot—80 MT of J55 and 65 MT of N80-1 seamless casing across 4-1/2" to 9-5/8" OD range with LTC connections. Mill-direct pricing gave us roughly 15% savings versus trading house quotes, which improved our resale margins significantly. All pipes passed our incoming inspection—wall thickness tolerances, OD measurements, and thread gauging were within spec. Delivery took 42 days for the custom sizes, slightly longer than expected but acceptable for the price point.

Mark Daniels

Australia

verified purchases

2025-03-17

Good Value T95 Tubing — Minor Documentation Delay
Purchased 70 MT of T95 seamless tubing, 3-1/2" OD with LTC connections for a CSG project in Queensland. Product quality was solid—hardness within NACE limits, full-body EMI inspection clean, and mechanical properties well within API 5CT specifications. Pricing was about 12% lower than our usual Japanese mill source. Only issue was the final mill test certificates arrived five days after the cargo, which caused a brief hold at customs. SteelPro acknowledged the delay and has since improved their document dispatch process. Would order again.

Ahmed Al-Rashidi

UAE

verified purchases

2025-04-08

Fast Stock Delivery for Urgent K55 Surface Casing Order
Needed 45 MT of K55 seamless casing, 13-3/8" OD with STC connections urgently for a surface casing job in Abu Dhabi. SteelPro confirmed stock availability same day and shipped within 9 business days—arrived at Jebel Ali port ahead of schedule. Drift test and hydrostatic test reports were included in the mill certificates. Varnish coating was applied evenly, and the pipes arrived in excellent condition with proper bundling and end caps. Pricing was competitive against three other quotes we received. Solid service for urgent requirements.

Sarah Jennings

United Kingdom

verified purchases

2025-04-30

Reliable Repeat Supplier — Fourth Order This Year
This is our fourth order with SteelPro in 2025. Latest purchase was 120 MT of N80-Q seamless casing, 7" OD in R3 lengths for our Aberdeen-managed drilling campaign. Consistency across batches has been outstanding—yield strength values tight within the 552–758 MPa range every time. Their sales team responds within hours, not days. Consolidated shipping to Felixstowe port saved us roughly 8% on logistics versus splitting across multiple suppliers. We've now made SteelPro our primary OCTG vendor for UK operations.

Oliver Hartmann

Germany

verified purchases

2025-05-22

Premium Threads Delivered Gas-Tight Seal at 9,500 PSI
Sourced 60 MT of C90 seamless OCTG casing with premium gas-tight connections for our North Sea offshore project. The metal-to-metal seal threads performed exactly as specified—zero leakage during our make-up torque testing at 9,500 psi. Full traceability from billet heat number to finished pipe was provided. Bureau Veritas witnessed the final inspection at the mill and confirmed compliance with ISO 11960. Custom stenciling with our project code was done accurately. Lead time was 38 days for this custom order, which was within the quoted window.

Dr. Rajan Mehta

India

verified purchases

2025-06-19

Excellent Sour Service L80 Tubing — NACE Compliant
We procured 95 MT of L80 seamless tubing, 2-7/8" OD for sour gas wells in our Cambay Basin project. Hardness consistently tested below HRC 22 as required by NACE MR0175. SSC test certificates were included with the EN 10204 Type 3.1 documentation without us even requesting separately. The phosphate coating quality was uniform across all bundles. SteelPro's technical team helped us select the correct wall thickness for our specific collapse pressure requirements. Very professional interaction from inquiry to delivery.

James Whitfield

United States

verified purchases

2025-07-04

P110 Casing Performed Flawlessly in HPHT Well
Ordered 180 MT of P110 seamless casing, 9-5/8" OD with BTC connections for a 14,000 ft HPHT well in West Texas. Every joint passed our third-party UT inspection with zero rejects. The API 5CT PSL2 mill certs were thorough—chemical composition, mechanical properties, hydrostatic test results all documented clearly. SteelPro delivered in 12 days from their stock, which saved us nearly two weeks compared to our previous supplier. Burst and collapse ratings exceeded API minimums. Will be specifying SteelPro for our next three well programs.