S390GD Steel Grades
High-Strength Galvanized Structural Steel for Construction and Industrial Applications
- Technical Support
S390GD Steel Technical Specifications & Applications
S390GD is a high-strength hot-dip galvanized structural steel grade compliant with EN 10346, offering a minimum yield strength of 390 MPa. It combines strength, formability, and corrosion resistance, making it suitable for various applications in construction and manufacturing.
This steel grade is widely used in structural framing, purlins, and heavy-duty roll-formed sections. Its excellent weldability and cold-forming properties allow for efficient processing in bending, cutting, stamping, and roll-forming operations.
Manufactured under stringent quality controls, S390GD meets international standards, ensuring reliable performance in galvanized and structural steel applications.
As a core product of Hengze Steel Group, S390GD is trusted globally for durable, high-performance galvanized structural steel solutions in construction, engineering, and manufacturing sectors.
Table of Contents
1. Typical Uses & Selection Guidance
- Structural Applications
S390GD is a high-strength hot-dip galvanized structural steel grade compliant with EN 10346, featuring a minimum yield strength of 390 MPa. It offers an optimal balance of strength, formability, and corrosion resistance, making it suitable for various applications in construction and manufacturing.
- Corrosion Protection
When hot-dip galvanized or metallic-coated (Zinc, Zinc-Aluminium), S390GD provides reliable corrosion resistance for roofing, wall cladding, gutters, and general building applications, particularly in mild to moderate environments. The zinc coating offers a robust barrier against corrosion, extending the life of the steel.
- Forming Advantages
The higher yield strength of S390GD allows for easier bending, tighter radii, and reduced risk of cracking, making it ideal for complex profiles, detailed fabrication, and applications requiring superior formability.
S390GD is characterized by its excellent combination of high strength, sufficient ductility, and long-lasting corrosion protection. The very high minimum yield strength ensures a high load-bearing capacity under dynamic and static loads. The elongation at break of at least 16% ensures sufficient deformability to compensate for stresses in profiling and bending processes and to prevent cracking.
2. Technical Specifications Table
1. Chemical Composition Requirements (Maximum %)
| Steel Grade | Carbon (C) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Silicon (Si) | Aluminum (Al) |
|---|---|---|---|---|---|---|
| S390GD | ≤ 0.20% | ≤ 1.70% | ≤ 0.10% | ≤ 0.045% | ≤ 0.60% | — |
2. Mechanical Property Requirements (Maximum Values)
| Steel Grade | Min. Yield Strength (MPa) | Min. Tensile Strength (MPa) | Min. Elongation (%) Lo=80mm | Bend Angle (°) | Mandrel Diameter (× Thickness t) |
|---|---|---|---|---|---|
| S390GD | ≥ 390 | 460–570 | ≥ 16 | 90 | 6t |
3. Coating Adhesion (180° Bend Test) Requirements
| Coating Class | Mandrel Diameter (× Thickness t) |
|---|---|
| Z100, Z200 | 1t |
| Z275, Z350, Z450, AZ150, AZ200, AM100, AM125, AM150, AM175, AM200, AM225 | 2t |
| Z600 | 3t |
4. Applicable Hot-Dip Metallic Coating Types
| Coating Class | Composition (%) | Key Features |
|---|---|---|
| Z (Zinc) | ≥99% Zinc | Basic corrosion protection; suitable for general use. |
| ZA (Zinc-Aluminium) | 95% Zn, 5% Al | Improved corrosion resistance over pure zinc. |
| ZF (Zinc-Iron) | Zinc with iron alloy | Enhanced hardness and wear resistance. |
| ZM (Zinc-Magnesium) | Zn with 2–4% Mg, 5–13% Al | Superior corrosion resistance in harsh environments. |
| AZ (Aluminium-Zinc) | 55% Al, 43.5% Zn, 1.5% Si | Excellent corrosion resistance and heat reflectivity. |
| AM (Aluminium-Magnesium) | Al with Mg alloy | High corrosion resistance; suitable for high-temperature applications. |
3. S390GD vs S550GD — What’s the Difference?
| Property | S390GD Steel Grade | S550GD Steel Grade |
|---|---|---|
| Yield Strength | ≥ 390 MPa | ≥ 550 MPa |
| Tensile Strength | 460–600 MPa | 560–720 MPa |
| Elongation (80mm) | ≥ 16% | ≥ 10% |
| Bendability | 180° with 6t mandrel | 180° with 6t mandrel |
S390GD Steel FAQ：
S390GD is a high-strength hot-dip galvanized structural steel grade compliant with EN 10346, with a minimum yield strength of 390 MPa. Its main mechanical properties include:
Yield Strength: ≥ 390 MPa
Tensile Strength: 460–600 MPa
Elongation (A80): ≥ 16%
This combination of strength, formability, and corrosion resistance makes it ideal for structural framing, heavy-duty roll-formed sections, and construction applications.
S390GD is widely used in construction, manufacturing, and industrial projects, including:
Structural framing: Beams, columns, and trusses
Roofing and façade systems: Trapezoidal and standing seam profiles
Infrastructure and bridges: Reinforcing sheets and girders
Agricultural and industrial equipment: Outdoor-exposed components
Solar energy structures: Photovoltaic mounting systems
Its high strength and cold-forming capabilities allow for efficient processing in bending, cutting, stamping, and roll-forming operations.
S390GD comes with various coatings to improve corrosion resistance:
Z (Zinc): Standard corrosion protection for general use
ZA (Zinc-Aluminium): Improved resistance in atmospheric conditions
ZF (Zinc-Iron): Enhanced adhesion and mechanical durability
ZM (Zinc-Magnesium): Superior protection in maritime or harsh environments
AZ (Aluminium-Zinc): Excellent corrosion resistance and heat reflectivity
Choosing the right coating depends on the environmental conditions and application requirements.
When welding S390GD steel, consider:
Preheating: Reduces hydrogen-induced cracking in thick sections
Welding consumables: Use electrodes or fillers compatible with high-strength galvanized steel
Post-weld treatment: Relieves residual stress and maintains mechanical properties
Safety measures: Zinc coating produces fumes; ensure proper ventilation
Following recommended welding standards and consulting specialists ensures optimal results.
