Product Overview
Black Welded Steel Pipe is manufactured through high-quality steel strip forming and welding processes to provide reliable strength, stable dimensions, and cost-effective solutions for structural and industrial applications.
Specifications
|
Project |
Black Welded Steel Pipe |
|
Standards |
GB/T 3091, GB/T 13793 (Equivalent international standards supported upon request) |
|
Steel Grades |
Q195, Q235B, Q355B (Equivalent to ASTM A500 / S235JR / S355JR options available) |
|
Length |
6m, custom lengths available |
|
Surface |
Standard hot-rolled black surface with natural mill scale (slight surface variations within commercial tolerances) |
|
Size |
Round Pipe: Φ10mm – Φ219mm Square Pipe: 10×10mm – 200×200mm Rectangular Pipe: 20×10mm – 200×150mm Wall Thickness: 0.75mm – 6.0mm |
|
Yield Strength |
195 to 345 MPa |
Key Advantages
Strict high-frequency electric resistance welding (ERW) maintains consistent outer diameters and uniform wall thicknesses from 0.75mm up to 6.0mm.
Broad portfolio including round pipes up to 219mm, square profiles up to 200x200mm, and rectangular tubes up to 200x150mm to satisfy one-stop project sourcing.
Clean black oxide surface finish minimizes pre-treatment cleaning and preparation time before secondary painting, powder coating, or cutting/welding fabrication.
Value-Added Processing Services
Precision Cutting: Custom fixed-length cutting with tight length tolerances.
End Treatment: Professional pipe end beveling, deburring, or thread cutting according to blueprint specifications.
Surface Protection: Optional application of temporary anti-rust varnish or protective oil coatings upon request.
Target Applications
Construction & Infrastructure: Scaffolding systems, temporary structural supports, and building frameworks.
Mechanical & Industrial Manufacturing: Machine parts, equipment chassis, and general structural fabrication.
Agricultural & Commercial Facilities: Greenhouse frames, fencing posts, and heavy-duty storage rack structures.
Low-Pressure Fluid Conveyance: Suitable for non-critical transport of water, air, or gas under compliant working pressures (subject to local code standards).
Quality Control Process
Incoming Material Inspection (IQC): Strict chemical and physical verification of primary Hot-Rolled Coils (HRC).
Online Welding Monitoring: Real-time high-frequency parameter tracking during the ERW forming process.
Non-Destructive Testing (NDT): 100% online eddy current testing on all welds to eliminate defects instantly.
Dimensional & Physical Testing: Batch sampling for tensile strength, elongation, flattening, and hydrostatic pressure.
Final Pre-Shipment Inspection: Surface finish, wall thickness tolerance, and anti-rust coating checks prior to bundling.
System Compliance Assurance: All manufacturing and testing procedures strictly follow ISO 9001 quality management system standards, maintaining a consistent product qualification rate of over 99.5%.
Global Supply & Export Logistics
Standard Seaworthy Bundling: Securely bundled with heavy-duty steel strips to prevent shifting or impact damage during long-distance maritime transport.
Moisture & Rust Protection: Lined with moisture-proof paper as standard. Export-grade anti-rust oil application or sealed plastic film wrapping is available upon request for high-humidity shipping routes.
Stable Supply Capacity: Continuous ERW production lines ensure stable monthly output with standard lead times of 15–25 days.
Container Loading & Shipping Guidelines
Weight Optimization: Steel tubes are heavy commodities. Standard 20GP or 40HQ containers are typically loaded up to the maximum payload limit (usually 25 to 27 metric tons) restricted by shipping lines and port regulations.
Mixed Loading Support: We specialize in combining multiple sizes, wall thicknesses, and profile types (round, square, rectangular) into a single container to optimize your inventory and freight costs.
FAQ
Q: What is the minimum order quantity (MOQ) for custom sizes or non-standard lengths?
A: We typically require a 3-ton minimum per size for custom lengths or special specifications, but we can combine mixed sizes in a single container for trial orders.
Q: Can you provide third-party inspection reports before shipment?
A: Yes, we fully support independent inspections by recognized agencies such as SGS, BV, or ISO-accredited laboratories prior to dispatch based on client requirements.
Q: What are your standard international payment terms for new wholesale clients?
A: We generally accept a 30% T/T deposit with the balance paid against the copy of the Bill of Lading, or an irrevocable L/C at sight for qualifying orders.
Q: Do you support custom pipe stenciling or marking?
A: Yes. We can spray-print standard details such as steel grades, sizes, batch numbers, production standards, or your own company logo directly onto each pipe according to your requirements.
Q: How is container stuffing handled to prevent transit damage?
A: Our professional loading team utilizes proper dunnage, wooden blocks, and steel wire securing techniques inside the container to prevent shifting, rolling, or structural bending during rough ocean transits.
Q: Can you provide the original Mill Test Certificate (MTC)?
A: Yes. Every shipment comes with an official Mill Test Certificate in compliance with the EN 10204 3.1 standard, detailing chemical composition and mechanical test results. We also fully support independent third-party inspections prior to dispatch.
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