304L vs 304H
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.
304L
Stainless Steel
304L is the low-carbon version of 304, specified for welded fabrications because its carbon cap of 0.030% prevents sensitisation in the heat-affected zone. It is the default 18-8 grade for welded chemical and food plant.
Standards: DIN 1.4307 · AISI 304L · JIS SUS304L · GB 022Cr19Ni10
304H
Stainless Steel
304H is the high-carbon variant of 304, with carbon held between 0.04 and 0.10% to guarantee creep-rupture strength at elevated temperature. It is specified for pressure parts in boilers and superheaters.
Standards: DIN 1.4948 · AISI 304H · JIS SUS304 · GB 07Cr19Ni10
Chemical composition compared (%)
| Element | 304L | 304H |
|---|---|---|
| C | ≤0.030 | 0.04–0.10 |
| Si | ≤0.75 | ≤0.75 |
| Mn | ≤2.00 | ≤2.00 |
| P | ≤0.045 | ≤0.045 |
| S | ≤0.030 | ≤0.030 |
| Cr | 18.00–20.00 | 18.00–20.00 |
| Ni | 8.00–12.00 | 8.00–10.50 |
| N | ≤0.10 | — |
Properties compared
| Property | 304L | 304H |
|---|---|---|
| Delivery condition | Annealed | Annealed |
| Hardness | ≤187 HB (annealed) | ≤187 HB (annealed) |
| Tensile strength | 485–690 MPa | 515–690 MPa |
| Yield strength | ≥170 MPa | — |
| Density | 7.90 g/cm³ | 7.90 g/cm³ |
| Creep service | — | Rated for pressure service above ~525 °C |
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: 304L · 304H. Substitution decisions for certified parts stay with the design authority.