Low-Carbon Seamless Steel Tubes are engineered for applications requiring high formability, consistent weldability, and strict dimensional accuracy under high pressure. Manufactured via hot rolling or cold drawing processes without a longitudinal weld seam, these tubes eliminate weak points prone to structural failure.
Specifications & Standards
|
Standard Grades |
ASTM A106 Gr. A/B, ASTM A179, EN 10305-1 (E235, E355), DIN 2391, JIS G3454 (STPG 370). |
|
Carbon Content |
<= 0.25% C (Optimized for welding and bending). |
|
Outer Diameter (OD) |
6 mm - 420 mm. |
|
Wall Thickness (WT) |
1 mm - 50 mm. |
|
Length |
5.8m, 6m, 11.8m, 12m, or custom cut-to-length. |
|
Delivery Condition |
Cold Drawn/Hard (+C), Cold Drawn/Soft (+LC), Cold Drawn/Stress Relieved (+SR), Annealed (+A), Normalized (+N). |
Material & Manufacturing Process
Steel Refining:
Electric Arc Furnace (EAF) + Ladle Refining (LF) + Vacuum Degassing (VD), controlling sulfur (<= 0.010%) and phosphorus (<= 0.015%) inclusions.
Hot Piercing & Rolling:
Rotary piercing of solid steel billets followed by mandrel mill rolling to ensure a uniform grain structure.
Precision Cold Drawing:
Multi-pass cold drawing benches with tungsten carbide dies, maintaining outer and inner diameter tolerances within +/- 0.08 mm.
Controlled Thermal Treatment:
Roller hearth furnaces for normalizing and stress relief under protective atmosphere, preventing scale formation and ensuring consistent hardness.
Quality Inspection & Testing
Non-Destructive Testing (NDT): 100% Eddy Current testing per ASTM E309 / EN 10246-3 and Ultrasonic testing (UT) for longitudinal/transverse flaws.
Dimensional Control: Automated laser scanning of outer diameter and wall thickness across the entire tube length.
Mechanical Testing: Tensile strength, yield strength, elongation, flattening, and flare/flange testing performed per production lot.
Traceability: Heat number, steel grade, size, and standard stenciled on each tube, fully traceable to EN 10204 3.1 Mill Test Certificates.
Typical Applications
Steering columns, propeller shaft components, shock absorber cylinders, and high-pressure fuel rail systems.
Hydraulic power lines, precision instrumentation tubing, and pneumatic cylinder barrels.
Heat exchangers, condensers, boiler economizers, and mechanical structural framing.
Customization & Supply Capabilities
Dimensional Customization: Non-standard outer diameters and custom wall-to-OD ratios drawn or machined to engineering drawings.
Surface Protection: Anti-rust solvent-based oil, phosphated and oiled interior/exterior, or passivated ends with plastic protective caps.
Export Packaging: Bundled with steel strapping, wrapped in heavy-duty waterproof woven fabric, or secured in seaworthy wooden crates.
Lead Time: 25-35 days for standard production runs; stocking programs available for contract buyers.
FAQ
Q: What is the maximum carbon equivalent (CE) for your low-carbon grades?
A: For standard grades like E235 and AISI 1020, the carbon equivalent is maintained below 0.35%, calculated via CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15, ensuring sound weldability without preheating.
Q: Can you supply tubes with tight eccentric tolerances for deep machining?
A: Yes. Cold-drawn precision tubes (EN 10305-1) maintain wall thickness eccentricity within +/- 5%, significantly reducing stock removal during ID/OD turning.
Q: What inspection documents are provided with the shipment?
A: Every shipment includes an EN 10204 3.1 Mill Test Certificate detailing chemical composition, mechanical properties, heat treatment charts, and NDT test results. Third-party inspection by SGS, BV, or TUV can be arranged prior to dispatch.
Q: What surface conditions are available for hydraulic applications?
A: Tubes can be supplied with bright annealed finish, phosphated and oiled internal/external surfaces to resist oxidation and improve corrosion resistance during storage.
Q: What is your standard MOQ for custom-sized production?
A: Minimum Order Quantity typically starts at 3 metric tons per size for non-standard dimensions. Smaller trial orders can be accommodated from existing stock inventories.
Q: How do you prevent corrosion during ocean freight?
A: Tubes are coated with solvent-based rust preventive oil, bundled securely with galvanized steel strips, and wrapped in moisture-barrier woven fabric. VCI bags are available upon request for containerized shipments.
Request a Quote
To receive an official commercial and technical proposal within 24 hours, please provide your exact specifications:
1.Steel Grade & Standard
2.Outer Diameter (OD) & Wall Thickness (WT)
3.Required Length & Quantity
4.Target Application & Destination Port
5.Direct Email: liuxudong@hrmgf.com
Online RFQ Form: [Link to Secure RFQ Submission Page]
Hot Tags: low-carbon seamless steel tubes, China low-carbon seamless steel tubes suppliers, factory
