Weather resistant steel, also commonly known as weathering steel, is a high-performance low-alloy structural steel. Unlike ordinary carbon steel, it can spontaneously form a dense, stable protective oxide film (patina) on its surface under suitable atmospheric environments. This unique patina layer tightly covers the steel substrate, effectively isolating air and moisture, significantly reducing electrochemical corrosion and minimizing long-term corrosion loss.
With excellent atmospheric corrosion resistance, high strength, good toughness and weldability, weathering steel is widely applied in bridge engineering, landscape architecture, iconic architectural structures, outdoor steel structures and other fields. The New River Gorge Bridge, a world-famous landmark structure, is a typical engineering case adopting weathering steel as the main structural material.
Weathering Steel Product Specification
| Product Category |
Spec Item |
Range / Standard Sizes |
Remarks |
| Steel Plate & Sheet |
Thickness |
1.5mm – 120mm |
Thin plate: 1.5–10mm; Medium plate: 10–40mm; Thick plate: 40–120mm; Custom ultra-thick plate available |
| |
Width |
1000mm – 3000mm |
Common widths: 1250mm, 1500mm, 1800mm, 2000mm, 2500mm, 3000mm |
| |
Length |
2000mm – 12000mm |
Custom fixed lengths; unlimited cutting for special lengths |
| Steel Coil |
Thickness |
1.2mm – 20mm |
- |
| |
Width |
1000mm, 1250mm, 1500mm, 1800mm, 2000mm |
Standard widths |
| |
Coil Weight |
3–15 tons per coil |
Custom coil weight supported |
| Flat Bar |
Thickness |
3–60mm |
- |
| |
Width |
20–300mm |
- |
| |
Length |
3000–6000mm |
- |
| Section Steel |
Types |
Angle steel, channel steel, H-beam, I-beam |
Full range of national & international standard specifications |
Available Standard Grades
Restrictions on Use
Weather resistant steel relies on atmospheric oxidation to form a protective rust layer. It is not suitable for the following environments, which will fail to form a stable patina and cause accelerated corrosion:
1. Highly Corrosive Industrial Environment: Environments with concentrated corrosive fumes, industrial pollution above ISO 9223 P3 level (SO₂ concentration > 250 μg/m³ or 200 mg/m² per day).
2. Persistent Wet & Damp Environment: Long-term continuous wet or damp conditions prevent the formation of protective oxide films, leading to rusting at the same rate as ordinary carbon steel.
3. High Chloride & Coastal Environment: Environments with salinity above ISO 9223 S2 level (Cl⁻ > 300 mg/m² per day). Extra caution is required for applications within 2 km of the coastline due to salt spray erosion.
4. De-icing Salt Contamination Environment: Scenarios with frequent de-icing salt usage, where chloride deposits accumulate heavily on steel surfaces, or salt-laden water directly flows over steel structures, and tunnel-like bridge spaces gather road salt spray.
5. Buried Environment: Not applicable for steel buried in soil or underground structures.
6. Low Clearance Overwater Environment: Not suitable for scenarios with steel headroom less than 2.5m above water. The standard applicable minimum headroom for weathering steel overwater bridges is 5.3m.
We support laser cutting, bending, drilling, polishing, rust stabilization treatment and patina pretreatment for all weathering steel products. Non-standard sizes and special-shaped parts can be customized according to customer drawings and engineering requirements.
