Huaxia-Steel is a premier factory-direct supplier of carbon steel seamless pipes for industrial, construction, and energy applications worldwide. We manufacture and export seamless carbon steel pipes conforming to ASTM A106, ASTM A53, API 5L, JIS G3454, and EN 10210 standards. With 20+ years of manufacturing experience, our seamless pipes are trusted by importers, distributors, and EPC contractors across Southeast Asia, the Middle East, Africa, and South America.
Product Overview
Seamless carbon steel pipes are manufactured by piercing a solid round billet to create a hollow tube, then rolling and sizing to final dimensions. Unlike welded pipes, seamless pipes have no longitudinal seam, providing uniform strength around the entire circumference. This makes them the preferred choice for high-pressure, high-temperature, and critical fluid transport applications where weld integrity is paramount.
Specifications & Dimensions
| Parameter | Range | Standard |
|---|---|---|
| Outer Diameter (OD) | 10.3mm – 1,219mm (1/8″ – 48″) | ASME B36.10M |
| Wall Thickness (WT) | 1.24mm – 100mm (Sch 5S – Sch XXS) | ASME B36.10M |
| Length | 5.8m, 6m, 11.8m, 12m, or random length | ASTM A530 |
| End Finish | Plain end, beveled end, threaded & coupled | ASTM A53 |
| Surface | Black, galvanized (HDG), varnished, 3LPE coated | Per customer spec |
Available Grades & Standards
We manufacture and supply seamless carbon steel pipes conforming to all major international standards. Our mill test certificates (MTC per EN 10204 3.1) are provided with every shipment:
| Standard | Grade | Typical Application | Temperature Range |
|---|---|---|---|
| ASTM A106 | Gr.A / Gr.B / Gr.C | High-temperature service, refineries, power plants | -29°C to 425°C |
| ASTM A53 | Gr.A / Gr.B | General purpose, structural, low-pressure fluid | -29°C to 200°C |
| API 5L | Gr.B / X42 / X52 / X60 | Oil & gas pipeline (PSL1 & PSL2) | -29°C to 200°C |
| JIS G3454 | STPG370 / STPG410 | Pressure service (Japanese standard) | -10°C to 350°C |
| EN 10210 | S235JRH / S355J2H | Structural hollow sections | -20°C to 200°C |
| ASTM A333 | Gr.1 / Gr.6 | Low-temperature service | -45°C to 200°C |
Mechanical Properties
| Grade | Yield Strength (min) | Tensile Strength (min) | Elongation (min) | Hardness (max) |
|---|---|---|---|---|
| ASTM A106 Gr.B | 240 MPa (35 ksi) | 415 MPa (60 ksi) | 30% (longitudinal) | — |
| ASTM A53 Gr.B | 240 MPa (35 ksi) | 415 MPa (60 ksi) | 30% | — |
| API 5L Gr.B | 245 MPa (35.5 ksi) | 415 MPa (60 ksi) | 23% (1,250mm²) | — |
| API 5L X52 | 360 MPa (52 ksi) | 460 MPa (67 ksi) | 21% | — |
| STPG370 | 215 MPa | 370 MPa | 30% (No.11 test piece) | — |
| EN S355J2H | 355 MPa | 470-630 MPa | 22% | — |
Quality Assurance
Every shipment undergoes rigorous quality control including:
- Hydrostatic Testing: Every pipe tested to 1.5× design pressure per ASTM A530/A530M. Standard test pressure up to 20.7 MPa (3,000 psi).
- Non-Destructive Testing (NDT): Eddy current, ultrasonic, or magnetic particle testing available per customer requirements.
- Dimensional Inspection: OD, wall thickness, length, straightness, and end squareness verified against ASME B36.10M tolerances.
- Chemical Analysis: Optical Emission Spectrometry (OES) for every heat, verifying C, Mn, Si, P, S, and residual element contents.
- Mechanical Testing: Tensile test, flattening test, bend test, and hardness test per applicable ASTM specifications.
Packaging & Shipping
Seamless pipes are bundled with steel straps, with end caps or bevel protectors on both ends to prevent damage during transit. Each bundle is tagged with heat number, grade, dimensions, and weight for traceability. Standard packaging options include:
- Bare Bundles: Steel strapped, plastic end caps, painted markings — most economical for container shipping.
- Wooden Crate: Full wooden case protection with internal separators — recommended for precision tubes.
- Hexagonal Bundling: For small-diameter pipes, hexagonal bundling maximizes container space utilization.
- Anti-Corrosion Wrapping: VCI (Volatile Corrosion Inhibitor) paper or film wrapping for sea freight protection.
Typical delivery lead time is 15-30 days from order confirmation, depending on quantity and specification complexity. We ship from major Chinese ports (Shanghai, Tianjin, Qingdao, Ningbo) with flexible FOB and CIF terms.
Ready to source high-quality carbon steel products at competitive factory-direct prices? Contact Huaxia-Steel today for a free quotation and consultation. Our team provides full Mill Test Certificates (MTC), third-party inspection reports, and flexible shipping options worldwide.
