Product Overview

Our hot rolled seamless steel pipes are manufactured from high-quality solid carbon steel and alloy steel billets through hot piercing and continuous hot rolling processes. Featuring a completely seamless structure with uniform mechanical properties across the full pipe body, this product delivers exceptional load-bearing capacity, high pressure resistance and reliable performance under harsh working conditions. As a fundamental industrial steel product, hot rolled seamless pipes are widely applied in fluid transmission, energy engineering, machinery manufacturing and structural construction projects worldwide.

Manufacturing Process

1. Raw Material Inspection: Solid round steel billets are strictly tested for chemical composition, surface defects and internal quality before production.

2. Heating: Billets are heated evenly to the optimal rolling temperature in a walking-beam heating furnace to guarantee stable plasticity.

3. Piercing: The heated billet is pierced into a hollow mother tube by a cross-roll piercing mill, forming the initial seamless hollow structure.

4. Hot Rolling: The hollow shell is processed through continuous rolling mills to reduce wall thickness and adjust outer diameter with high precision.

5. Sizing & Reducing: The semi-finished pipe passes through a sizing mill to achieve the final outer diameter and strict dimensional tolerance.

6. Finishing & Inspection: After cooling, the pipes go through straightening, surface finishing, non-destructive testing, hydrostatic test and final quality verification before packaging.

Key Features

· Integral seamless structure: No weld seam eliminates leakage and fracture risks at welding joints, ensuring higher structural integrity and operational safety.

· Uniform mechanical performance: Homogeneous grain structure and consistent wall thickness deliver excellent tensile strength, yield strength and impact toughness.

· High pressure & temperature resistance: Suitable for conveying high-pressure fluids and long-term operation in high-temperature industrial environments.

· Wide material compatibility: Available in carbon steel, low-alloy steel and heat-resistant alloy steel to adapt to diverse working scenarios.

· Stable dimensional accuracy: Controlled hot rolling process ensures tight tolerances on outer diameter, wall thickness and straightness.

· Customization support: Custom dimensions, length specifications and surface treatments are available to match specific project requirements.

Main Applications

· Oil & Gas industry: Onshore and offshore oil/gas gathering pipelines, well casing and tubing, crude oil and natural gas transmission lines.

· Power generation: Boiler tubes, superheater tubes, high-pressure steam pipelines for thermal power and nuclear power plants.

· Petrochemical & chemical industry: Process piping for corrosive fluid delivery, refinery equipment pipelines and chemical reactor components.

· Mechanical engineering: Hydraulic cylinder tubes, automotive structural parts, machinery bearing sleeves and equipment fabrication.

· Construction & structure: Steel structure columns, bridge components, underground pile foundations and scaffolding systems.

· Municipal engineering: Urban water supply and drainage pipelines, natural gas distribution networks and district heating pipelines.

· Shipbuilding & marine engineering: Hull structural pipes, marine fluid transmission systems and offshore platform piping.

Standards & Specifications

Applicable Standards

· ASTM / ASME: A106 Gr.A/B/C, A53 Gr.B, A333 Gr.1/3/6, A335 P11/P22/P91

· API Spec 5L: Gr.B, X42, X46, X52, X56, X60, X65, X70 (PSL1 / PSL2)

· DIN: DIN 1629 St37.0 / St44.0 / St52.0; DIN 17175

· GB: GB/T 8163, GB/T 3087, GB/T 5310, GB/T 6479

Dimension Range

· Outer Diameter: 21.3 mm – 630 mm (custom sizes up to 1020 mm available upon request)

· Wall Thickness: 2.5 mm – 60 mm

· Length: 6m / 12m fixed length, or random length as per customer requirements

Common Steel Grades

· Carbon steel: 10#, 20#, 45#, Q235B, Q355B, A106 Gr.B, API 5L Gr.B, St37, St52

· Low alloy steel: 16Mn, Q345B/C/D/E, A333 Gr.6

· Alloy steel: 15CrMo, 12Cr1MoV, Cr5Mo, P11, P22, P91

Quality Assurance

All hot rolled seamless steel pipes are produced under an ISO 9001 certified quality management system. Each batch undergoes strict inspection procedures including hydrostatic pressure testing, ultrasonic testing (UT), magnetic particle testing (MT), eddy current testing (ET), spectral analysis and dimensional verification. Third-party inspection by SGS, BV, TÜV and other authoritative institutions is available upon customer request.

We provide professional technical support and flexible global delivery solutions for distributors, engineering contractors and end-users. For detailed quotations and product catalogs, please contact our sales team directly.