Stainless Steel 304H
AISI/SAE 304H · UNS S30409 · EN 1.4948 · GB 07Cr19Ni10
304H is the carbon-controlled version of 304 (UNS S30409, 07Cr19Ni10), in which the higher carbon level is specified to raise creep strength for elevated-temperature service up to 815 °C.
Values for the Solution Annealed condition
304H tempers and conditions
304H is supplied in 4 conditions, soft to hard. Solution Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged and solution annealed | Flanges, fittings and valve bodies forged then solution annealed for ASME high-temperature piping systems. | 250 | 565 | 50 | 155 HB | 2.4 % IACS |
Solution AnnealedDefault 1040–1120 °C, rapid quench | Standard supply condition for plate, tube and forgings used in ASME high-temperature service; maximum ductility and carbide dissolution. | 260 | 585 | 55 | 150 HB | — |
mill annealed sheet/strip/bar | General mill-annealed condition for sheet, strip and bar where the ASME coarse-grain solution treatment is not separately certified. | 265 | 580 | 53 | 155 HB | 2.4 % IACS |
cold finished bar/tube (annealed + light draw) | Choose for straight, close-tolerance bar or tube where higher yield strength and better surface finish are needed below the sensitization range. | 450 | 690 | 32 | 18 HRC | 2.4 % IACS |
Supply forms, finishes and certifications
Ways 304H is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CRA 2B | Cold rolled, annealed, 2B finish sheet | Surface finish |
HRAP | Hot rolled, annealed and pickled plate | Surface finish |
What is 304H?
304H is the carbon-controlled version of 304 (UNS S30409, 07Cr19Ni10), in which the higher carbon level is specified to raise creep strength for elevated-temperature service up to 815 °C. It is used for code pressure equipment and is stocked as plate, sheet, bar and forgings in annealed, solution annealed, HRAP, CRA 2B, cold drawn and forged + SA conditions; annealed material gives 260 MPa yield, 585 MPa tensile, 55 % elongation and 150 HB with formability rated 90. The same carbon raises sensitization risk between 425 and 870 °C, so weld with 308H filler and cool quickly; 321H or 347H are the alternatives when stabilisation against intergranular attack is required. 304H has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F). 304H has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
What is 304H used for?
- Pressure vessels
- Welded boiler tubes
- Superheater and reheater components
- High-temperature process piping and flanges
- Heat exchanger shells
- Furnace hardware and supports
- Refinery pipework fittings
Advantages
- Forms and bends easily — 90/100, better than 98% of stainless steel grades
- Ductile — tolerates forming and impact — 55%, better than 97% of stainless steel grades
- Tough — resists crack growth — 220 MPa·√m (200.2 ksi·√in), better than 97% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
- Readily welded — 85/100, better than 87% of stainless steel grades
Limitations
- Low strength — 260 MPa (37.7 ksi), worse than 84% of stainless steel grades
304H properties
Typical room-temperature values for 304H-Solution Annealed; bars are the position among stainless steel grades.
Physical3
304H has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
304H has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
304H is rated for continuous service to 815°C (1,499 °F). It conducts heat at 16.2 W/m·K (9.36 BTU/hr·ft·°F), better than 64% of stainless steel grades. Thermal expansion is 17.3 µm/m·K (9.61 µin/in·°F).
Electrical3
304H conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 304H takes about 53 MJ of energy and emits 4.5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 65%.
Manufacturability8
304H's machinability is fair (40/100, better than 72% of stainless steel grades); weldability excellent (85/100); formability excellent (90/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 304H is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 304H
Is 304H easy to machine?
Gummy and work-hardening like 304 — use rigid setups, positive-rake sharp carbide, heavy constant feed and flood coolant; ~45 % of AISI 1212.
Can 304H be welded?
Readily welded by GTAW/GMAW/SMAW with 308H filler to match creep strength; no preheat, keep interpass low, and remember the high carbon means sensitization risk if slow-cooled through 425–870 °C.
Can 304H be formed, bent or molded?
Excellent cold formability (deep drawing, roll forming, bending), but high work-hardening rate demands more power and generous bend radii; hot work at 1150–1200 °C then solution anneal.
Manufacturability
The process limits FabDigit applies to 304H. Every 304H part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair40 / 100 |
|---|---|
| ISO material group | M.1 |
| Cutting speed (rough / finish) | 150 / 180 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 4× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better90 / 100 |
|---|---|
| Weldability | Excellent85 / 100 |
| Bendable | Yes |
304H chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Craised carbon is the defining feature of the H grade | 0.04 – 0.1 | 0.06 |
| Mn | ≤ 2 | 1.5 |
| Si | ≤ 0.75 | 0.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Cr | 18 – 20 | 18.5 |
| Ni | 8 – 10.5 | 9 |
| N | ≤ 0.1 | 0.05 |
| Fe | balance |
What surface finishes work on 304H?
Not anodizable; passivate per ASTM A967, or pickle/electropolish welds — mechanical polishing to No.4/No.8 is straightforward.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Organic Coating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 304H in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S30409
- EN / DIN / Werkstoff-Nr.
- 1.4948
- GB (China)
- 07Cr19Ni10
How much does 304H cost?
304H is a premium-cost stainless steel ($$$), pricier than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
304H — frequently asked
What is 304H used for?
304H is typically used for pressure vessels, welded boiler tubes, superheater and reheater components, high-temperature process piping and flanges, heat exchanger shells and furnace hardware and supports. In short: high-temp 304 plate.
What is the yield strength of 304H?
304H has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 84% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 304H easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Gummy and work-hardening like 304 — use rigid setups, positive-rake sharp carbide, heavy constant feed and flood coolant; ~45 % of AISI 1212.
Can 304H be welded?
Yes — weldability is rated excellent (85/100). Readily welded by GTAW/GMAW/SMAW with 308H filler to match creep strength; no preheat, keep interpass low, and remember the high carbon means sensitization risk if slow-cooled through 425–870 °C.
What surface finishes work on 304H?
Not anodizable; passivate per ASTM A967, or pickle/electropolish welds — mechanical polishing to No.4/No.8 is straightforward.
Can 304H be formed, bent or molded?
Excellent cold formability (deep drawing, roll forming, bending), but high work-hardening rate demands more power and generous bend radii; hot work at 1150–1200 °C then solution anneal.
What is the maximum service temperature of 304H?
304H is rated for continuous use to about 815°C (1,499 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 304H cost?
304H is a premium-cost stainless steel ($$$), pricier than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 304H?
Yes — 304H is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A213/A213M — Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater and Heat-Exchanger Tubes — ASTM International (2022)
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges and Fittings — ASTM International (2022)
- ASME BPVC Section II Part D — Materials, Properties — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Outokumpu Corrosion Handbook / Stainless Steel Datasheets — Outokumpu (2021)
- EN 10028-7 (1.4948 X6CrNi18-10) — CEN (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.