What is SPA-H Anti Corrosion Steel Sheet?
JIS G3125 specifies the technical requirements for high weathering-resistant hot-rolled steel plates used in structural and container manufacturing, with SPA-H Corten Steel classified as a low-alloy high-strength weathering steel grade.
By adding alloying elements such as copper (Cu), chromium (Cr), and nickel (Ni), SPA-H forms a dense and stable protective patina layer on the steel surface, providing excellent atmospheric corrosion resistance.
Its corrosion resistance is approximately 4–8 times higher than that of ordinary carbon steel, helping reduce corrosion rates and maintenance requirements.
SPA-H also offers high strength, good weldability, and formability, with a yield strength of ≥355 MPa and tensile strength of 490–610 MPa. With its low-maintenance and long-service-life characteristics, SPA-H is widely used in shipping containers, railway vehicles, architectural structures, and other weathering steel applications exposed to outdoor environments for extended periods.
GNEE provides SPA-H weathering steel plates in various thicknesses, widths, and lengths to meet different project requirements. We offer value-added services including CNC cutting, laser cutting, bending, drilling, and custom fabrication.
Each shipment comes with an EN 10204 3.1 Mill Test Certificate (MTC), and additional inspections such as ultrasonic testing (UT) and third-party inspection by SGS, BV, or TUV are available upon request.
JIS G3125 SPA-H Weathering Steel Plate Specifications
| Item | Description |
|---|---|
| Standard | JIS G3125 |
| Material Grade | SPA-H High-Strength Weathering Steel |
| Steel Type | Low-Alloy Atmospheric Corrosion-Resistant Structural Steel |
| Product Form | Hot Rolled Steel Plate, Sheet, and Coil |
| Thickness | 1.6 mm – 100 mm (Customized Available) |
| Width | 1,000 mm – 3,200 mm (Customized Available) |
| Length | 2,000 mm – 12,000 mm (Customized Available) |
| Manufacturing Process | Hot Rolled, Pickled, Shot Blasted (Optional) |
| Surface Condition | Hot Rolled Surface, Pickled Surface, Shot Blasted Surface |
| Yield Strength | ≥355 MPa |
| Tensile Strength | 490–610 MPa |
| Elongation | ≥21% (Depending on Thickness) |
| Main Alloy Elements | Copper (Cu), Chromium (Cr), Nickel (Ni) |
| Atmospheric Corrosion Resistance | Approx. 4–8 Times Higher Than Ordinary Carbon Steel |
| Processing Service | Cutting, Drilling, Bending, Welding Preparation, Customized Fabrication |
| Inspection | Chemical Composition Analysis, Mechanical Testing, Dimensional Inspection, Surface Inspection, UT Testing (Optional) |
| Certification | Mill Test Certificate (MTC), EN 10204 3.1 / 3.2 (Available Upon Request) |
Chemical Composition of JIS G3125 SPA-H Weathering Steel
| Element | Chemical Composition (%) |
|---|---|
| Carbon (C) | ≤0.12 |
| Silicon (Si) | ≤0.75 |
| Manganese (Mn) | ≤1.00 |
| Phosphorus (P) | ≤0.035 |
| Sulfur (S) | ≤0.035 |
| Copper (Cu) | 0.25–0.55 |
| Chromium (Cr) | 0.30–1.25 |
| Nickel (Ni) | 0.12–0.65 |
| Iron (Fe) | Balance |
Physical Properties of JIS G3125 SPA-H Weathering Steel
| Property | Typical Value |
|---|---|
| Density | Approx. 7.85 g/cm³ |
| Melting Point | Approx. 1,450–1,520°C |
| Elastic Modulus | Approx. 200 GPa |
| Thermal Conductivity | Approx. 40–50 W/(m·K) |
| Specific Heat Capacity | Approx. 460–500 J/(kg·K) |
| Poisson's Ratio | Approx. 0.30 |
| Thermal Expansion Coefficient | Approx. 11.7 × 10⁻⁶ /°C (20–100°C) |
| Electrical Resistivity | Approx. 0.15–0.20 μΩ·m |
| Magnetic Property | Ferromagnetic (may vary with processing conditions) |
| Atmospheric Corrosion Resistance | Approx. 4–8 times higher than ordinary carbon steel |
Mechanical Properties of JIS G3125 SPA-H Weathering Steel
| Property | Requirement |
|---|---|
| Yield Strength (YS) | ≥355 MPa |
| Tensile Strength (TS) | 490–610 MPa |
| Elongation (L≥50mm) | ≥21% |
| Brinell Hardness (HB) | Approx. 140–200 HB (Typical) |
| Impact Test Temperature | -20°C (when required) |
| Elastic Modulus | Approx. 200 GPa |
| Fatigue Strength | Depends on plate thickness, welding condition, and design stress |
What is between the SPA-H And SPA-C Weathering Steel?
SPA-H and SPA-C are both JIS G3125 weathering steels with similar atmospheric corrosion resistance. The main difference is their mechanical strength.
SPA-H offers higher strength with a yield strength of ≥355 MPa and tensile strength of 490–610 MPa, making it suitable for heavy-duty applications such as shipping containers and railway structures.
SPA-C has a yield strength of ≥295 MPa and tensile strength of ≥400 MPa, providing good corrosion resistance and formability for general outdoor structures.
What is the equivalent grade of SPA-H?
SPA-H weathering steel is a high-strength atmospheric corrosion-resistant steel specified under JIS G3125. Its comparable grades include Q355GNH, S355J2W, ASTM A588 Grade A, and ASTM A242 Type 1.
With a yield strength of ≥355 MPa and tensile strength of 490–610 MPa, SPA-H offers mechanical properties similar to these grades. However, differences in chemical composition and technical standards mean they are not directly interchangeable.
Applications of SPA-C Weathering Steel
Shipping Containers: Container side panels, roof panels, floors, doors, and structural frames requiring long-term corrosion resistance.
Railway Vehicles: Freight wagons, container flatcars, and rail transport structural components exposed to outdoor environments.
Weathering Steel Fabrication: Cut, bent, welded, and fabricated components for outdoor structural and industrial projects.
Need SPA-H weathering steel plates for your architectural or outdoor structural projects? GNEE provides high-quality SPA-H steel plates with custom cutting, bending, fabrication, and surface treatment services. Contact us today for a professional solution and quotation.
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SPA-H Corten Steel Plate Processing Services
To help customers reduce fabrication time and overall project costs, GNEE provides comprehensive value-added processing services for SPA-H weathering steel plates.
Laser Cutting
High-precision CNC laser cutting for complex shapes, holes, slots, and custom profiles according to customer drawings.
CNC Bending & Forming
Precision bending, folding, and forming services for architectural panels, planter boxes, retaining walls, and custom weathering steel components.
Drilling & Punching
Accurate drilling, countersinking, and punching for bolts, connections, and assembly requirements.
Welding & Fabrication
Custom welding and structural fabrication for finished weathering steel products and assemblies.
Pre-Rusted Surface Treatment
Accelerated weathering treatment to create a uniform, stable rust patina before delivery, reducing on-site waiting time.
Edge Milling & Beveling
Professional edge preparation and beveling for welding applications, improving fabrication efficiency.
SPA-H Corten Steel Plate Testing and Quality Assurance
Every SPA-H weathering steel plate is subjected to strict quality inspections to ensure compliance with JIS G3125 standards and customer specifications.
Chemical Composition Analysis:
Spectrometer analysis is performed to verify the content of alloying elements such as Cu, Cr, Ni, and P, ensuring the steel meets SPA-H chemical composition requirements.
Mechanical Property Testing:
Yield strength, tensile strength, elongation, and impact toughness tests are conducted to ensure stable mechanical performance and structural reliability.
Dimensional & Surface Inspection:
Thickness, width, length, flatness, and surface condition are carefully inspected to guarantee accurate dimensions and a defect-free finish.
Ultrasonic Testing (UT) (Optional):
Ultrasonic inspection can be provided according to EN 10160 or customer requirements to detect internal defects in thick plates.
Mill Test Certificate (MTC):
Each shipment is supplied with an EN 10204 3.1 Mill Test Certificate. Third-party inspections by SGS, BV, TUV, or other agencies are also available upon request.
SPA-H Weathering Steel Packaging And Shipping
GNEE supplies SPA-H weathering steel with standard export bundling. Steel plates are stacked and securely fastened with steel straps, with protective materials added between plates when required to prevent scratches and surface damage during transportation.
For special requirements, we can also provide additional packaging solutions, including waterproof wrapping, edge protection, wooden supports, and reinforced container loading.
Each bundle is clearly marked with steel grade, dimensions, heat number, and quantity to ensure easy identification and full traceability during shipment.
