How to Select: SPA‑H vs S355J2W
Select S355J2W (EN 10025‑5) for EU‑governed infrastructure, cold‑climate and heavy‑duty structural projects requiring Charpy impact certification at ‑20 °C. Choose SPA‑H (JIS G3125) for Asian‑market projects, containers, building facades, sculptures and mild coastal decorative applications, where a uniform aesthetic patina is prioritized. Do not blindly substitute one grade for the other, as there are substantial differences in standard compliance and low‑temperature performance.
What is Weathering Steel?
Weathering steel, commonly referred to as Corten steel, is a low‑alloy steel with copper, chromium and nickel additions. Subject to cyclic wet‑and‑dry outdoor atmospheric exposure, a dense, tightly adherent protective oxide layer (known as patina) gradually forms on its surface. This patina blocks further penetration of oxygen and moisture, greatly reducing the corrosion rate. Compared with plain carbon steel, it delivers considerable long‑term savings in painting and maintenance costs.
What is SPA‑H? (JIS G3125)
SPA‑H is a Japanese hot‑rolled weathering steel complying with JIS G3125. "SPA" stands for Steel Plate Atmospheric‑resistance; "H" denotes the hot‑rolled delivery condition. Its elevated phosphorus content facilitates rapid development of an evenly toned reddish‑brown patina, making it widely adopted in construction and container manufacturing. The original standard contains no mandatory requirement for ‑20 °C low‑temperature Charpy impact toughness.
What is S355J2W? (EN 10025‑5, 1.8965)
S355J2W is the European structural weathering steel specified under EN 10025‑5. Grade designation breakdown:
- S: Structural steel
- 355: Minimum yield strength ≥ 355 MPa (for thickness ≤ 16 mm)
- J2: Mandatory Charpy V‑notch impact energy ≥ 27 J at ‑20 °C
- W: Weather‑resistant grade
Stringent limits are imposed on phosphorus content for structural‑safety purposes. Engineered for heavy‑load bearing structures in cold inland and industrial environments, this grade is extensively used for public‑infrastructure projects within the European Union.
If you require complete certified data sheets for SPA‑H or S355J2W, including heat‑number chemical analyses and mechanical‑property test records, please contact GNEE Steel for free sample Material Test Certificates (MTC) for your project review.
SPA‑H vs S355J2W: Patina Formation and Atmospheric Corrosion Behaviour
SPA‑H Weathering Steel Plate
- Patina formation cycle: A stable reddish‑brown surface patina develops within 6‑12 months under natural cyclic wet‑dry atmospheric conditions.
- Its high‑phosphorus alloy composition produces a fine‑grained, uniform and aesthetically pleasing corroded surface, which is highly favoured for building facades and art installations.
- Suitable environments: Mild coastal zones (within 5 km from the coastline), urban atmospheres and moderately industrial environments.
- Limitations: Not suitable for heavy salt‑spray coastal environments; no guaranteed resistance against low‑temperature brittle fracture.
S355J2W Weathering Steel Plate
- Patina formation cycle: A fully stabilised dark chocolate‑brown protective patina takes 1.5‑3 years to develop; noticeable colour variation occurs during the early corrosion stage.
- Formulated with low phosphorus, it prioritises structural performance over decorative surface uniformity.
- Suitable environments: Inland industrial zones, cold high‑altitude regions and heavy‑duty outdoor steel structures.
- Limitations: Bare S355J2W is not recommended for heavy salt‑spray coastal service. Uneven patina colour in early‑stage weathering makes it less suitable for high‑end facades with strict visual‑quality requirements.
SPA-H S355J2W Weather Resistant Steel Plate Specification
|
Product Name |
SPA-H S355J2W Weather Resistant Steel Plate |
|
Length |
as required |
|
Width |
0.6m-3m or as required |
|
Thickness |
3mm-100mm or as required |
|
Standard |
JIS, EN |
|
Technique |
Hot rolled |
|
Surface Treatment |
according to customer requirement |
|
Thickness tolerance |
±0.1mm |
|
Material |
S355J2W, SPA-H |
SPA‑H vs S355J2W Corten Steel Plate Chemical Composition
| Element | SPA‑H (JIS G3125) | S355J2W (EN 10025‑5) |
|---|---|---|
| C | ≤0.12 | ≤0.16 |
| Si | 0.20‑0.75 | 0.30‑0.50 |
| Mn | ≤0.60 | 0.50‑1.50 |
| P | 0.07‑0.15 | ≤0.030 |
| S | ≤0.035 | ≤0.030 |
| Cu | 0.25‑0.55 | 0.25‑0.55 |
| Cr | 0.30‑1.25 | 0.40‑0.80 |
| Ni | ≤0.65 | ≤0.65 |
SPA‑H vs S355J2W Corten Steel Plate Mechanical Property
| Property | SPA‑H (JIS G3125) t≤16 mm | S355J2W (EN 10025‑5) t≤16 mm |
|---|---|---|
| Yield Strength ReH (MPa) | ≥355 | ≥355 |
| Tensile Strength Rm (MPa) | ≥490 | 470‑630 |
| Elongation A (%) | ≥22 (t≤6 mm) | ≥22 |
| Charpy Impact | No mandatory‑20 °C requirement | ≥27 J @‑20 °C |
| Delivery Condition | Hot‑rolled | Hot‑rolled / Normalized |
SPA‑H vs S355J2W High Strength Steel Plate Welding & Fabrication Performance
| Item | SPA‑H | S355J2W |
|---|---|---|
| Welding Consumables | Weathering‑matching Cu‑Cr‑Ni filler metals recommended; avoid ordinary carbon‑steel wire for long‑term corrosion resistance | Low‑alloy high‑strength consumables acceptable; dedicated weathering wire preferred for optimum joint patina |
| Pre‑heating | Pre‑heat ≥80 °C for plate >20 mm | Pre‑heat 80‑100 °C for thickness >25 mm to prevent cold cracking |
| Cold‑bending performance | Good for thin gauges (<6 mm); larger bending radius for thick plates | Excellent cold‑formability, fits standard structural‑steel workshop processes |
| Carbon Equivalent | Moderate | CEV ≤0.52 (t≤25.4 mm) |
Practical note: Weld joints always corrode faster than base metal; proper filler selection and post‑weld surface treatment extend service life for both grades.
SPA‑H vs S355J2W Corten Plate Typical Applications
Typical Applications for SPA‑H
- Shipping containers and railway wagon bodies
- Building curtain walls, weathering‑steel sculptures and urban landscape installations
- Guardrails and outdoor decorative structures for projects in Southeast Asia, Japan, South Korea and China
- Decorative facades in mild coastal areas (non‑primary load‑bearing structures)
Typical Applications for S355J2W
- EU‑compliant highway and railway steel bridges, secondary support structures for wind‑turbine towers
- Frames for heavy‑duty outdoor machinery and port machinery structures
- Municipal steel structures for cold high‑altitude locations
- Dynamically‑loaded load‑bearing structures requiring ‑20 °C Charpy impact certification
SPA‑H vs S355J2W Corten Plate Application Selection Guideline
| Project Condition | Recommended Grade |
|---|---|
| EU public infrastructure / bridge,‑20 °C design requirement | S355J2W |
| Nordic / high‑altitude cold‑region load‑bearing steel | S355J2W |
| Container manufacturing, Asian railway carriages | SPA‑H |
| Art sculpture & building facade (visual priority) | SPA‑H |
| Mild‑coastal decorative non‑load‑bearing cladding | SPA‑H |
| Heavy‑salt coastal bare‑steel structures | Neither grade |
If you are unsure which grade fits your site environment and local code, send your project location, design temperature and load type to GNEE Steel for free technical assessment.
SPA‑H vs S355J2W High Strength Corten Steel Plate Cost Comparison
| Comparison Item | SPA‑H | S355J2W |
|---|---|---|
| FOB price range (USD/MT) | 440‑520 | 480‑570 |
| Raw‑material alloy cost | Medium | Slightly higher |
| Third‑party inspection cost | Standard | Higher (mandatory low‑temperature impact test) |
| Project compliance risk cost | Higher for European bids | Low for EU projects |
| Total cost of ownership (mild‑climate decoration) | Lower | Higher |
Disclaimer: Actual price fluctuates with raw‑material, thickness, order quantity, inspection requirements. Contact GNEE Steel for real‑time formal quotation.
Supply & Services from GNEE Steel
With 18 years of export experience in weathering steel plates, GNEE Steel supplies hot‑rolled plates and coils of SPA‑H and S355J2W to clients worldwide across Southeast Asia, EU, Latin America and the Middle East:
Stock & dimensions: Stock thickness range: 2‑100 mm; custom lengths and widths available; delivery conditions: hot‑rolled / normalised. ‑ Complete quality documentation: Mill Material Test Certificates (MTC, EN 10204‑3.1B), batch traceability records, chemical composition and mechanical test reports; third‑party witnessed pre‑shipment inspection is available upon request.
Export‑grade packaging: Waterproof paper, anti‑rust film, fumigated wooden pallets / steel frame bundling, suitable for long‑distance containerised ocean freight.
FAQ
What is the equivalent material for S355J2W steel?
S355J2W (EN 10025-5) is a weather-resistant structural steel equivalent to Corten B, ASTM A588 Grade B (US), GB/T Q355NH / Q355GNH (China), and JIS G3125 SPA-H (Japan).
What is the difference between S355J0W and S355J2W?
S355J0W and S355J2W are both European standard (EN 10025-5) structural weathering steels with the same minimum yield strength (355 MPa) and atmospheric corrosion resistance. The primary difference is their low-temperature impact toughness testing: S355J0W is tested at 0°C, while S355J2W is tested at -20°C.
Can SPA-H steel be welded?
Yes, SPA-H steel can be welded. It is a weathering steel (often compared to Corten-A) with low carbon content, which gives it good overall weldability for common applications like shipping containers and architectural panels.
What is the hardness of SPA-H material?
The typical Brinell hardness of SPA-H weathering steel (JIS G3125) in the as-rolled condition is approximately 150 to 200 HB.
