Zhongji Metal
Diverse Product Range · Reliable Quality · Tailored Solutions
Covering various types of steel products such as steel pipes, steel plates, steel coils, steel bars, and structural steel
meeting the diverse needs of different industries.
Product Description
Technical & Material Properties
Base Material Grades: Q195, Q235, Q345, ASTM A53 Grade A/B, BS 1387.
Manufacturing Methods: ERW (Electric Resistance Welded), Seamless (Hot Rolled/Cold Drawn).
Outer Diameter Range: 15 mm – 273 mm (½" – 10").
Wall Thickness: 1.0 mm – 12.0 mm.
Zinc Coating Weight:
Hot-dip: 200–600 g/m² (average coating thickness 30–85 μm)
Electro-galvanized: 40–120 g/m²
Tensile Strength: 350–550 MPa.
Yield Strength: 235–345 MPa.
Coating Adhesion: Meets ISO 1461 or ASTM A123 requirements for cross-hatch adhesion tests.
Surface Finish: Smooth zinc coating, minimal spangle, optionally passivated or oiled for extended storage life.
Manufacturing Process & Standards
Manufacturing Process:
Steel coil or billet preparation and forming into round section
High-frequency welding (ERW) or seamless pipe extrusion
Pickling to remove mill scale
Hot-dip galvanizing in molten zinc bath at ~450°C or electro-galvanizing
Cooling, passivation, and inspection
Standards:
ASTM A53, ASTM A123 (coating)
BS EN 10240 (internal/external coating)
GB/T 3091 (welded steel pipe for low pressure fluid)
Inspection:
Coating thickness and weight (magnetic gauge or weighing method)
Hydrostatic pressure test for fluid-carrying pipes
Bend and flattening tests
Visual inspection for coating defects and weld seam integrity
Packaging: Bundled with steel straps, capped ends to prevent debris entry, optional plastic wrap for extra corrosion protection.
Product Real Shot

Packaging and Shipping

Applications & Advantages
Applications:
Structural frameworks for greenhouses, scaffolding, and guardrails
Water supply and drainage systems (non-potable)
Outdoor poles, signposts, and fencing systems
Automotive exhaust systems (in some low-cost designs)
Advantages:
Zinc coating provides sacrificial corrosion protection, even if scratched
High strength-to-weight ratio suitable for load-bearing applications
Long service life (20–50 years depending on environment and coating weight)
Minimal maintenance requirements compared to painted steel pipes
Example Case: In coastal fencing projects, hot-dip galvanized round pipes with Z500 coating have shown over 30 years of service without significant rusting.
FAQ
Q1: What product information must I provide before making a purchase?
A: Please provide the material, size, surface treatment requirements, and the quantities you need.
Q2: What about product pricing information?
A: Prices may vary due to fluctuations in raw material costs.
Q3: Is it possible to send samples?
A: Yes, we offer free samples with express shipping worldwide.
Q4: Do you offer a service for customized products?
A: Yes, we can supply according to your specific requirements.
Q5: Can I visit you in person?
A: Customers from all over the world are welcome to meet with us.
Q6: Can you assist me in importing steel products for the first time?
A: Yes, we can provide support through our experienced shipping agents.
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Reliable Quality – All products are made with premium raw materials, advanced equipment, and strict quality inspections before delivery.
Compliance Guarantee – Specifications strictly follow technical agreements, ensuring products are free from defects in design, materials, and workmanship.
After-sales Service – Dedicated teams provide timely response, technical consultation, and long-term support.
Global Commitment – We serve clients in over 50 countries with consistent quality and reliable service.

First class quality service and professional after-sales team.
*We respect your confidentiality and all information are protected.