When engineers and procurement managers require a material that combines structural integrity with long-term corrosion resistance, the S350GD structural galvanized steel coil is a top-tier choice. This hot dip galvanized coil offers a minimum yield strength of 350 MPa, making it ideal for load-bearing components in construction, automotive, and energy sectors. At ChinaCNU Steel, our Qingdao factory produces S350GD+Z275 coils with precise zinc coating control, ISO-certified quality, and competitive FOB pricing. With over 15 years of export experience to 80+ countries, we supply GI coil that meets strict international standards, with a standard MOQ of 25 tons per specification.
What Is S350GD Structural Galvanized Steel Coil?
S350GD is a structural grade designation under EN 10346, indicating a minimum yield strength of 350 MPa. The “GD” stands for “Galvanized Drawing,” though this grade is primarily used for structural rather than deep drawing applications. When combined with a zinc coating like Z275 (275 g/m² total both sides), the S350GD structural galvanized steel coil delivers exceptional resistance to atmospheric corrosion. The hot dip galvanizing process ensures a metallurgical bond between the steel substrate and the zinc layer, preventing spalling during forming or bending.
S350Gd Structural Galvanized Steel Coil Price Trend (USD/Ton) – Last 12 Months
Data: ChinaCNU Steel Market Research | FOB Tianjin Reference Price
Common LSI keywords associated with this product include GI coil, zinc coating Z60 Z120 Z275, hot dip galvanized coil, and galvanized steel supplier. The material is frequently specified for purlins, roofing sheets, wall panels, and structural framing in industrial and commercial buildings. The zinc coating weight directly influences service life—Z275 offers robust protection in moderate to aggressive environments, while lighter coatings like Z60 or Z120 are suitable for indoor applications.
Mechanical Properties and Chemical Composition
The steel base of S350GD is micro-alloyed to achieve high strength without sacrificing formability. Typical mechanical properties include:
- Yield strength: 350 MPa minimum
- Tensile strength: 420–520 MPa
- Elongation: 18% minimum (A80)
- Zinc coating: Z60, Z120, Z180, Z275 (specify per order)
- Surface finish: Regular spangle, minimized spangle, or zero spangle
Chemical composition is tightly controlled with low carbon (≤0.20%) and small additions of manganese, phosphorus, and silicon to achieve the strength requirements. The hot dip galvanized coil undergoes continuous annealing and galvanizing in a single line, ensuring uniform mechanical properties across the entire coil length.
Why Choose S350GD+Z275 Over Standard Grades?
Compared to lower-strength grades like DX51D or S250GD, the S350GD structural galvanized steel coil offers a superior strength-to-weight ratio. This allows engineers to reduce material thickness by 15–30% while maintaining structural performance, leading to significant cost savings in transportation and erection. The Z275 coating provides 275 g/m² of zinc, delivering approximately 15–20 years of maintenance-free service in rural environments and 8–12 years in industrial or coastal areas.
For projects requiring enhanced corrosion resistance, ChinaCNU Steel can supply GI coil with Z350 or even Z600 coatings. However, Z275 remains the most cost-effective choice for structural applications where both strength and durability are critical. Our galvanized steel supplier team provides detailed coating weight certifications with every shipment, ensuring compliance with EN 10346 and ASTM A653 standards.
Comparison of Coating Weights and Applications
| Coating Designation | Total Zinc Mass (g/m²) | Typical Service Life (Years)* | Recommended Applications | Relative Cost |
|---|---|---|---|---|
| Z60 | 60 | 3–5 | Indoor dry environments, temporary structures | Lowest |
| Z120 | 120 | 6–10 | Roofing, wall cladding (moderate exposure) | Low |
| Z180 | 180 | 10–15 | Agricultural buildings, exterior panels | Medium |
| Z275 | 275 | 15–20 | Structural framing, purlins, bridges | Optimal |
| Z350 | 350 | 20–25 | Marine environments, chemical plants | High |
*Service life estimates based on rural atmosphere; actual performance varies with environment.
Applications of S350GD Structural Galvanized Steel Coil
The high strength and corrosion resistance of S350GD make it suitable for a wide range of structural applications. In the construction industry, it is commonly used for cold-formed steel sections such as C-purlins, Z-purlins, and steel studs. These components form the backbone of modern steel-framed buildings, warehouses, and industrial sheds. The hot dip galvanized coil can be roll-formed, punched, and cut without damaging the zinc coating, enabling efficient prefabrication.
In the energy sector, S350GD is specified for solar panel mounting structures, wind turbine towers, and electrical enclosures. The material’s ability to withstand cyclic loading and environmental stress makes it a reliable choice for renewable energy projects. Additionally, the automotive industry uses this GI coil for chassis components, brackets, and reinforcement parts where weight reduction is essential.
ChinaCNU Steel exports S350GD structural galvanized steel coil to over 50 countries, including markets in Europe, Southeast Asia, Africa, and the Americas. Our Qingdao factory operates with ISO 9001 and ISO 14001 certifications, ensuring consistent quality and environmental compliance. With 15+ years of export experience, we understand the logistics of international shipping and can arrange FOB, CIF, or DDP terms to suit your project timeline.
Quality Assurance and Certifications
Every coil produced at our Qingdao facility undergoes rigorous testing to verify mechanical properties, coating thickness, and surface quality. Our quality control lab performs tensile tests, bend tests, and salt spray tests to ensure the S350GD structural galvanized steel coil meets EN 10346 and ASTM A653 requirements. We provide mill test certificates (MTC) with each shipment, including heat numbers and coating weight analysis.
Our ISO certification covers all production stages, from hot rolling and cold rolling to continuous galvanizing and slitting. This ensures traceability and repeatability for large-scale projects. For buyers requiring specific surface treatments—such as passivation, oiling, or anti-fingerprint coating—we can customize the finish to prevent white rust during storage and transit.
Frequently Asked Questions (FAQ)
1. What is the difference between S350GD and S250GD?
S350GD has a minimum yield strength of 350 MPa, while S250GD has 250 MPa. The higher strength allows S350GD to be used in thinner gauges for load-bearing applications, reducing overall material weight and cost. Both grades are galvanized, but S350GD is preferred for structural framing and purlins.
2. Can I order S350GD with different zinc coating weights?
Yes, ChinaCNU Steel offers S350GD with coating weights from Z60 to Z600. The most common for structural use is Z275, but we can adjust based on your environmental exposure and budget. Contact our team to discuss your specific requirements for GI coil.
3. What is the standard MOQ for S350GD structural galvanized steel coil?
Our standard MOQ is 25 tons per specification (thickness, width, and coating weight). For mixed containers or smaller trial orders, we can accommodate sample quantities. For large projects, we offer volume discounts and flexible delivery schedules.
4. How does FOB pricing work for coils from Qingdao factory?
FOB Tianjin pricing includes the cost of the steel coil, inland transport to the port, and export documentation. We provide a full FOB quotation with estimated shipping costs to your destination port. Payment terms are typically T/T or L/C at sight for first-time buyers.
5. Is S350GD suitable for marine environments?
For marine or highly corrosive environments, we recommend S350GD with a heavier zinc coating such as Z350 or Z600, combined with additional protective measures like paint or sealants. The base steel’s strength remains beneficial, but the coating weight must be increased to resist salt spray and humidity.
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