Corten A vs SPA-H
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
Corten A
Structural & HSLA Steel
Corten A is the original weathering steel composition (Cu-Cr-Ni-P alloyed), forming a dense, self-protecting rust layer that removes the need for painting. The high phosphorus content suits plate and sheet; it is the architectural and container industry’s standard weathering grade.
Standards: DIN S355J0WP type (EN 10025-5) · AISI A242 type (near) · JIS SPA-H (near) · GB 09CuPCrNi-A (near)
SPA-H
Structural & HSLA Steel
SPA-H is the JIS G3125 hot-rolled weathering steel — Japan’s Corten A equivalent, mass-produced for containers, vehicles and architecture. Its Cu-Cr-Ni-P analysis mirrors the original US Steel weathering composition.
Standards: DIN S355J0WP type (near) · AISI A242 type (near) · JIS SPA-H (JIS G3125) · GB 09CuPCrNi-A (near)
Chemical composition compared (%)
| Element | Corten A | SPA-H |
|---|---|---|
| C | ≤0.12 | ≤0.12 |
| Si | 0.25–0.75 | 0.25–0.75 |
| Mn | 0.20–0.50 | ≤0.60 |
| P | 0.07–0.15 | 0.070–0.150 |
| S | ≤0.035 | ≤0.035 |
| Cr | 0.30–1.25 | 0.30–1.25 |
| Ni | ≤0.65 | ≤0.65 |
| Cu | 0.25–0.55 | 0.25–0.55 |
Properties compared
| Property | Corten A | SPA-H |
|---|---|---|
| Yield strength | ≥355 MPa | ≥355 MPa |
| Tensile strength | 470–630 MPa | ≥490 MPa |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: Corten A · SPA-H. Substitution decisions for certified parts stay with the design authority.