What is SPA-H Atmospheric Corrosion Resisting Steel?
JIS G3125 specifies the technical requirements for high weathering resistance hot-rolled steel plates, sheets, and strips, covering weathering steel grades such as SPA-H.
By adding alloying elements such as Cu, Cr, and Ni, weathering steel can form a stable protective patina layer in atmospheric environments, with a corrosion rate typically reduced to about 1/2–1/4 of that of ordinary carbon steel, significantly improving outdoor service life.
SPA-H hot-rolled weathering steel plate is a low-alloy weather-resistant structural steel that complies with JIS G3125 standards and offers excellent atmospheric corrosion resistance. Its typical composition includes Cu (0.25–0.55%), Cr (0.45–0.75%), and Ni (0.10–0.40%).
It is widely used in bridges, architectural facades, railway vehicles, containers, and outdoor steel structures exposed to long-term environmental conditions.
As a professional weathering steel supplier, GNEE provides SPA-H hot rolled weathering steel plates with various thicknesses and sizes to meet different fabrication requirements.
We offer customized processing services, including cutting, leveling, drilling, bending, welding, and surface treatment for Corten steel architectural products.
Each batch of SPA-H steel is strictly inspected to ensure compliance with JIS G3125 and international standards, and we provide EN 10204 3.1 material test certificates (MTC) for full quality traceability.
For architectural facade applications, SPA-H weathering steel provides excellent atmospheric corrosion resistance and long-term durability. Through alloying elements such as Cu, Cr, and Ni, the steel surface gradually forms a dense and stable protective patina layer, reducing the need for painting and regular maintenance.
With a typical yield strength of ≥355 MPa and tensile strength of 490–630 MPa, SPA-H offers excellent structural strength and processing performance, making it suitable for laser cutting, bending, welding, and fabrication into customized Corten steel facades, screens, panels, sculptures, and outdoor architectural structures.
Its natural rust finish provides a unique aesthetic appearance while protecting the steel substrate from further corrosion, making SPA-H an ideal material for modern buildings, landscape projects, and exterior decorative applications requiring both durability and visual appeal.
Specification of SPA-H Atmospheric Corrosion Resisting Steel
| Parameter | Description |
|---|---|
| Grade | SPA-H |
| Classification | High Weathering Resistance Steel / Atmospheric Corrosion Resistant Steel |
| Standard | JIS G3125 (High Atmospheric Corrosion Resistant Rolled Steel) |
| Equivalent Grades | ASTM A588, ASTM A242 (Approx.) |
| Delivery Condition | Hot Rolled, As Rolled or Customized Surface Treatment |
| Thickness | 3.0 mm – 100 mm |
| Width | 1500 mm – 2500 mm (Customized Available) |
| Length | 3000 mm, 6000 mm, 12000 mm (Customized Available) |
| Edge Condition | Mill Edge or Cut Edge |
| Surface Finish | Hot Rolled Surface, Shot Blasted, Rusted Surface Treatment Available |
Chemical Composition of JIS G3125 SPA-H Corten Steel Plate
| Grade | SPA-H |
|---|---|
| S ≤ | 0.035 |
| Cu | 0.25~0.55 |
| C ≤ | 0.12 |
| P | 0.070~0.150 |
| Si | 0.20~0.75 |
| Mn | ≤0.60 |
| Cr | 0.30~1.25 |
| Ni ≤ | 0.65 |
Mechanical Properties of SPA-H Corten Steel Sheet
| Grade | SPA-H | |
|---|---|---|
| PlateThickness | ≤6.0mm | >6.0mm |
| Tensilestrength | ≥490MPa | ≥490MPa |
| Yieldstrength | ≥355MPa | ≥355MPa |
| Elongation | ≥22 | ≥15 |
SPA-H Weathering Steel Plate Tolerance
| Thickness width | 1600 < 2000 | Less than 1600 |
|---|---|---|
| 2.50 < 3.15 | ±0.29 | ±0.22 |
| 3.15 < 4.00 | ±0.34 | ±0.24 |
| 4.00 < 5.00 | ±0.55 | ±0.45 |
| 1.60 < 2.00 | ±0.23 | ±0.19 |
| 10.0 < 16.0 | ±0.65 | ±0.55 |
| < 1.25 | － | ±0.16 |
| 2.00 < 2.50 | ±0.25 | ±0.20 |
| 5.00 < 6.30 | ±0.60 | ±0.50 |
| 6.30 < 10.0 | ±0.65 | ±0.55 |
| 1.25 < 1.60 | － | ±0.18 |
| 16.0 < 25.0 | ±0.75 | ±0.65 |
SPA-H Steel Hot Rolled Plate Bendability
| Parameter | Typical Value |
|---|---|
| Bending Angle | 180° |
| Inner Bending Radius | ≥ 1.5 × Thickness (t) |
| Test Condition | Cold Bending |
| Crack Requirement | No cracks on the outer surface after bending |
What is difference between the SPA-H Steel And SPA-C Steel
The main difference between SPA-H and SPA-C steel is their mechanical properties. SPA-H has a yield strength of ≥355 MPa and tensile strength of 490–630 MPa, while SPA-C has a yield strength of ≥275 MPa and tensile strength of 410–540 MPa.
SPA-H is commonly used for architectural facades, bridges, and heavy steel structures, while SPA-C is suitable for general outdoor structures and weather-resistant applications. Both grades develop a stable protective patina layer to improve atmospheric corrosion resistance.
What is the difference between SPA-H Steel and Q355GNH Steel?
The main differences between SPA-H and Q355GNH steel are their standards, chemical composition, and application markets. SPA-H is a Japanese weathering steel grade specified by JIS G3125, while Q355GNH is a Chinese weathering steel grade specified by GB/T 4171.
SPA-H is mainly used in Japanese-standard projects and architectural applications, while Q355GNH is widely applied in Chinese infrastructure projects such as bridges and heavy steel structures.
What is the difference between SPA-H Steel and ASTM A588 Steel?
The main difference is the standard and mechanical properties. SPA-H complies with JIS G3125, with a yield strength of ≥355 MPa and tensile strength of 490–630 MPa.
ASTM A588 complies with ASTM standards, with a yield strength of ≥345 MPa and tensile strength of 485–620 MPa. SPA-H has slightly higher strength requirements, while ASTM A588 is more commonly used in North American structural applications.
Applications of SPA-H Weathering Steel Plate
Architectural Facades and Cladding: Used for Corten steel curtain walls, exterior panels, decorative screens, and building facades, providing a natural rust appearance and long-term weather resistance.
Landscape and Outdoor Structures: Applied in garden edging, planters, sculptures, fences, and outdoor artistic installations, combining durability with a unique patina finish.
Customized Fabrication Parts: Suitable for laser cutting, bending, welding, and other fabrication processes to produce customized weathering steel components for architectural and landscape projects.
Public and Industrial Structures: Used in bridges, railway facilities, outdoor steel structures, and other applications requiring corrosion resistance and reduced maintenance.
SPA-H Weathering Steel Plate Price Reference
| Item | Specification | Price Reference (USD/MT) |
|---|---|---|
| SPA-H Raw Steel Plate | 3–10 mm thickness | $1,000–1,300 / MT |
| SPA-H Raw Steel Plate | 12–25 mm thickness | $950–1,250 / MT |
| SPA-H Raw Steel Plate | 30–50 mm thickness | $1,000–1,350 / MT |
| SPA-H Raw Steel Plate | 50–100 mm thickness | $1,100–1,500 / MT |
| Processing Service | Description | Price Reference |
|---|---|---|
| Cutting Service | Laser cutting / CNC cutting | $50–150 / MT |
| Plate Cutting to Size | Customized plate dimensions | $30–100 / MT |
| Drilling Service | Bolt holes / customized holes | $0.5–3 / hole |
| Bending Service | CNC bending for facade panels and components | $80–250 / MT |
| Welding Service | Customized welding fabrication | $100–400 / MT |
| Shot Blasting | Surface cleaning and preparation | $30–80 / MT |
| Rusted Surface Treatment | Accelerated patina/rust finish | $50–150 / MT |
| Full Fabrication Service | Cutting + welding + finishing + assembly | $200–800 / MT |
Note: Prices are for reference only. Final quotations depend on SPA-H steel plate thickness, order quantity, drawings, tolerance requirements, surface finish, and shipping terms.
From raw plates to finished Corten steel facades, GNEE provides professional cutting, welding, and surface treatment services. Contact us now for a customized quotation.
Get Your Custom SPA-H Weathering Steel Solution Today
立即获取您的定制SPA-H耐候钢解决方案
Lead Time of SPA-H steel plate
| Order Type | Lead Time |
|---|---|
| In-stock SPA-H Steel Plate | Typically 5–10 business days for quality verification, cutting, packing, and shipment arrangements |
| Mill Production / Custom Orders | Typically 30–60 days depending on order quantity and specifications |
| Cutting & Fabrication Services | Additional 7–20 days depending on processing requirements, including cutting, drilling, bending, welding, and surface treatment |
| Rust Surface Treatment | Additional 7–15 days for accelerated patina development and finishing |
Quality Inspection
To ensure SPA-H weathering steel meets JIS G3125 and customer requirements, the following inspections are typically performed:
- Chemical Composition Analysis: Testing alloying elements including Cu, Cr, Ni, and other elements to verify material grade.
- Mechanical Property Testing: Tensile test, yield strength test, elongation test, hardness test, and bending test.
- Dimensional Inspection: Verification of thickness, width, length, flatness, and tolerance using professional measuring equipment.
- Surface Inspection: Checking surface conditions for defects, cracks, rust layer quality, scratches, and other abnormalities.
- Ultrasonic Testing (UT): Optional inspection to detect internal defects for critical structural applications.
- PMI (Positive Material Identification): On-site material verification using a handheld spectrometer to confirm SPA-H grade and prevent material mix-ups.
- Material Certification: Providing EN 10204 3.1 Material Test Certificate (MTC) for chemical composition, mechanical properties, and traceability.
Packaging of SPA-H Weathering Steel
SPA-H weathering steel are packed using standard export methods, with steel straps and waterproof materials to ensure safe transportation and prevent damage.
Customized packaging solutions, including wooden cases or steel frames for fabricated parts, are available according to customer requirements. All packages are labeled with product grade, size, quantity, and heat number for easy identification and traceability.
