DH36 vs AH36
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.
DH36
Structural & HSLA Steel
DH36 is the −20 °C impact version of the 355 MPa hull grade, specified for vessels trading in cold waters and for exposed structure where AH36 toughness is insufficient. Chemistry is the same family as AH36; the difference is the toughness guarantee and its verification.
Standards: AISI A131 DH36 · JIS KD36 (near) · GB DH36 (GB/T 712)
AH36
Structural & HSLA Steel
AH36 is the most used high-tensile hull steel in the world — the 355 MPa grade that modern bulk carriers, tankers and container ships are built from. Strength and 0 °C toughness are certified plate-by-plate by the classification society.
Standards: AISI A131 AH36 · JIS KA36 (near) · GB AH36 (GB/T 712)
Chemical composition compared (%)
| Element | DH36 | AH36 |
|---|---|---|
| C | ≤0.18 | ≤0.18 |
| Si | ≤0.50 | ≤0.50 |
| Mn | 0.90–1.60 | 0.90–1.60 |
| P | ≤0.035 | ≤0.035 |
| S | ≤0.035 | ≤0.035 |
| Note | Nb/V/Ti grain-refining per class rules | Nb/V/Ti grain-refining per class rules |
Properties compared
| Property | DH36 | AH36 |
|---|---|---|
| Yield strength | ≥355 MPa | ≥355 MPa |
| Tensile strength | 490–630 MPa | 490–630 MPa |
| Impact | −20 °C, ≥34 J longitudinal (≤50 mm) | 0 °C, ≥34 J longitudinal (≤50 mm) |
| 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: DH36 · AH36. Substitution decisions for certified parts stay with the design authority.