254 SMO vs 904L
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.
254 SMO
Stainless Steel
254 SMO is a 6% molybdenum super-austenitic stainless with nitrogen and copper, giving a PREN above 42. It was developed for seawater and hot chloride service where 316L pits and even 904L runs out of margin.
Standards: DIN 1.4547 · AISI UNS S31254 (254 SMO) · GB 015Cr20Ni18Mo6CuN
904L
Stainless Steel
904L is a high-nickel, molybdenum- and copper-bearing super-austenitic stainless developed for sulfuric acid and hot chloride service. Copper gives it resistance to reducing acids that defeat 316L, while 4–5% molybdenum covers pitting.
Standards: DIN 1.4539 · AISI 904L (UNS N08904) · GB 015Cr21Ni26Mo5Cu2
Chemical composition compared (%)
| Element | 254 SMO | 904L |
|---|---|---|
| C | ≤0.020 | ≤0.020 |
| Si | ≤0.80 | ≤1.00 |
| Mn | ≤1.00 | ≤2.00 |
| P | ≤0.030 | ≤0.045 |
| S | ≤0.010 | ≤0.035 |
| Cr | 19.50–20.50 | 19.00–23.00 |
| Ni | 17.50–18.50 | 23.00–28.00 |
| Mo | 6.00–6.50 | 4.00–5.00 |
| Cu | 0.50–1.00 | 1.00–2.00 |
| N | 0.18–0.22 | ≤0.10 |
Properties compared
| Property | 254 SMO | 904L |
|---|---|---|
| Delivery condition | Solution annealed | Annealed |
| Hardness | ≤220 HB (annealed) | ≤217 HB (annealed) |
| Tensile strength | ≥690 MPa | 490–690 MPa |
| Yield strength | ≥310 MPa | — |
| Density | 8.00 g/cm³ | 7.90 g/cm³ |
| PREN | ≥42 | ~35 |
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: 254 SMO · 904L. Substitution decisions for certified parts stay with the design authority.