304H
Data verified304H 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.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.04–0.10 |
| Si | ≤0.75 |
| Mn | ≤2.00 |
| P | ≤0.045 |
| S | ≤0.030 |
| Cr | 18.00–20.00 |
| Ni | 8.00–10.50 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Hardness | ≤187 HB (annealed) |
| Tensile strength | 515–690 MPa |
| Density | 7.90 g/cm³ |
| Creep service | Rated for pressure service above ~525 °C |
Heat treatment
Solution anneal 1040–1120 °C, rapid cool; grain size is controlled coarser for creep strength.
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.4948 |
| aisi | 304H |
| jis | SUS304 |
| gb | 07Cr19Ni10 |
Compare side by side: 304H vs 304 · 304H vs 304L
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Superheater and reheater tubes, boiler pressure parts, high-temperature process piping, heat exchangers.
Processing: Weldable with standard austenitic practice; the higher carbon makes it more prone to sensitisation than 304L, so it is not the choice for corrosive welded service at ambient temperature.
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Ask for a quotationVisit NasteelSource: ASTM A240 / EN 10088 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.