Seamless Steel Pipe ( Round / Square / Rectangular Hollow Seamless Tube)
Seamless steel pipe is integrally perforated & rolled from solid steel billet without any welding seam, covering round, square and rectangular hollow sections. Featuring uniform overall strength, high pressure & temperature resistance. We supply hot rolled & cold drawn seamless tubes, support galvanizing, cutting and custom sizing for high-pressure pipeline and load-bearing structural engineering.
Available Grades
- ASTM A53 Gr.B Carbon Seamless Pipe: Universal low-carbon seamless grade, balanced ductility and pressure resistance, widely used for general fluid conveyance and common structural framing projects.
- ASTM A106 Gr.B High-temperature Seamless Pipe: Heat-resistant optimized grade, stable performance under high heat, dedicated for boiler, heat exchanger and high-temperature industrial piping systems.
- Q235B / S235JR Structural Seamless Hollow: Cost-effective forming grade, neat corner forming for seamless square/rectangular tube, ideal for building frame and outdoor load-bearing structures.
- Q355B / S355JR High-strength Seamless Pipe: Low-alloy reinforced grade, superior compression and torsion resistance, applied for heavy machinery base, bridge and engineering load-bearing components.
- 42CrMo Alloy Seamless Pipe: Heat-treatable alloy grade, excellent fatigue & impact resistance, customized for automotive shaft, hydraulic cylinder and extreme working condition parts.
- 20# Hot Rolled Standard Seamless Pipe: Domestic mainstream carbon grade, stable metallurgical structure, suitable for conventional oil, water, gas medium high-pressure delivery pipelines.
Product Features
- Seamless Integral Molding: No welding joint or weak weld point, uniform wall stress, avoid cracking, leakage and fracture under high pressure or torsion load.
- Three Complete Cross-section Shapes: Round pipe for fluid transport; square & rectangular tube for structural support, meet piping and architectural dual usage demands.
- Superior High Pressure & Heat Resistance: Withstand far higher working pressure than welded pipe, stable performance under high temperature, low temperature and alternating load environment.
- Precision Dimensional Tolerance: Cold drawn finished seamless tube owns tight size tolerance, smooth inner & outer surface, easy machining, threading and assembly processing.
- Strong Corrosion Adaptability: Dense integral steel texture slows medium erosion; optional hot dipped galvanized finish upgrades outdoor anti-rust service performance.
- Uniform Mechanical Performance: Consistent hardness and tensile strength in all directions, no partial strength defect for long-term cyclic service scenarios.
Applications
- Petrochemical High-pressure Pipeline: Seamless round pipe for crude oil, natural gas, chemical medium transmission, adapt high-pressure and slight corrosive industrial working conditions.
- Boiler & Thermal Power System: High-temperature resistant seamless round tube for boiler water wall, superheater and thermal station circulating high-temperature piping.
- Building Steel Structure Works: Seamless square/rectangular tube for high-rise building support, stadium frame, villa steel structure and heavy-load building bearing framework.
- Mechanical & Automotive Components: Precision seamless tube for hydraulic cylinder, automobile axle, machinery arm and custom machined hollow mechanical parts.
- Offshore & Coastal Engineering: Thick-wall galvanized seamless hollow section for offshore platform support, coastal guardrail, resist salt fog and seawater splash corrosion.
- Hydraulic & Pneumatic Industry: Precision cold drawn seamless round pipe for hydraulic pipeline, air pressure conveying pipeline, guarantee zero leakage fluid transmission.
Product Advantages (Customer Value)
- Lower Project Failure Risk: No weld weakness, greatly reduce pipeline leakage, structural fracture accidents, cut project safety hidden troubles for contractors.
- Extend Whole Service Lifespan: 2-4 times longer service life than ordinary welded pipe, reduce periodic replacement, maintenance and shutdown repair cost for clients.
- Pass Strict Engineering Audit Easily: Standard mechanical property and batch test report meet international petroleum, boiler, construction industry bidding acceptance standards.
Technical Data Table
| Technical Item | Ordinary Carbon Seamless | High Strength Seamless | Alloy Seamless Pipe |
| Material Density | 7.85 g/cm³ | 7.85 g/cm³ | 7.87 g/cm³ |
| Yield Strength | ≥245 MPa | ≥355 MPa | ≥540 MPa |
| Tensile Strength | 410–550 MPa | 470–630 MPa | 750–980 MPa |
| Elongation | ≥20% | ≥16% | ≥12% |
| Max Working Pressure | 16MPa | 25MPa | 42MPa |
| Available Section | Round/Square/Rectangular | Round/Square/Rectangular | Round Custom Hollow |
Why Choose Us
- Full-section Seamless Stock: Stock round, square, rectangular seamless tubes in multiple grades, support mixed-section container shipment for integrated engineering orders.
- Full-item Strict Quality Testing: Conduct hydraulic pressure test, ultrasonic flaw detection, mechanical test for every batch, zero defective seamless products delivered.
- Custom Integrated Processing: Offer fixed-length cutting, chamfering, galvanizing, threading and surface polishing, supply finished pipes for direct installation.
- Professional Material Selection Guide: Recommend matched grade & wall thickness based on pressure, temperature and usage scene, optimize customer procurement budget.
- Mill Direct Stable Supply: Own hot rolling & cold drawing seamless production lines, no middle dealers, stable quotation and priority bulk delivery service.
Packaging & Shipping
- Standard Seaworthy Export Package: Small size seamless tubes bundled with steel strips; large size tubes equipped with plastic end caps; wrapped waterproof kraft paper and woven cloth for sea moisture & collision protection.
- Permanent Laser Marking: Laser print grade, size, wall thickness, heat number and batch info on pipe surface for convenient receiving and quality traceability.
- Custom Protective Packing: Anti-rust oil coating, PE film full wrapping, private brand logo printing for high-precision cold drawn seamless tubes.
- Reasonable Delivery Cycle: Standard size seamless pipe 4-7 working days delivery; custom size & galvanized seamless hollow tube 12-18 working days production lead time.
FAQ
- Q: What is the difference between seamless and welded steel pipe?
A: Seamless pipe has no weld seam, higher pressure resistance and longer service life, fit high-pressure/high-temperature working conditions; welded pipe is cost-effective for ordinary low-pressure use. - Q: What scenarios use square/rectangular seamless tube?
A: Mainly used for building steel frame, machinery support, fence structure and architectural decoration, better bearing performance than welded hollow section. - Q: Can you customize special size seamless pipe?
A: Yes, we support custom outer diameter, wall thickness, length and corner radian for non-standard round, square and rectangular seamless tubes. - Q: Does seamless pipe support hot dip galvanized treatment?
A: Sure, we provide internal and external hot dipped galvanized treatment to improve outdoor anti-corrosion and anti-rust capability. - Q: Which grade is best for boiler piping system?
A: ASTM A106 Gr.B and 20# hot rolled seamless round pipe are the most recommended grades for industrial boiler high-temperature piping.
