ASTM A240 Type 304H Stainless Steel Sheet & Plate
What is ASTM A240 Type 304H Stainless Steel Sheet and Plate?
As a production and export expert at SHH STEEL, we are pleased to present our ASTM A240 Type 304H Stainless Steel Sheet and Plate, also known as SS304H, UNS S30409, or SUS304H. This high-carbon version of Type 304 is specifically developed under the ASTM A240 / ASME SA240 specification for improved strength and creep resistance at elevated temperatures.
Unlike standard Type 304 and 304L, ASTM A240 Type 304H has a controlled higher carbon content (0.04–0.10%), which enhances its high-temperature mechanical properties. It is widely used in applications involving continuous service at temperatures above 500°C, such as heat exchangers, superheaters, boilers, and furnace parts. SHH STEEL supplies ASTM A240 304H stainless steel plate and ASTM A240 304H sheet in thicknesses from 0.5 mm to 100 mm, with widths up to 2500 mm and lengths up to 12000 mm. Custom sizes are available upon request.
Our ASTM A240 Type 304H products are typically supplied in the annealed condition, offering a good balance of high-temperature strength, oxidation resistance, and fabricability. All material comes with Mill Test Certificates (EN 10204 3.1) for complete traceability. Whether you need thin 304H stainless steel sheet or thick 304H stainless steel plate, SHH STEEL provides reliable quality for demanding high-temperature projects worldwide.
Material Specification ASTM A240 Type 304H
ASTM A240 Type 304H stainless steel sheet and plate are manufactured in accordance with ASTM A240/A240M and ASME SA240. This specification covers chromium-nickel stainless steel plate, sheet, and strip for pressure vessels and high-temperature applications. SHH STEEL offers material in annealed condition with common surface finishes such as 2B, No.1, and BA. Thickness ranges from 0.5 mm to 100 mm, with custom dimensions available.
| Specification Element | Requirement | SHH STEEL Compliance | Keywords |
|---|---|---|---|
| Primary Standard | ASTM A240 / ASME SA240 Type 304H | Full compliance | ASTM A240 304H specification |
| Product Form | Sheet & Plate | Both available | ASTM A240 304H sheet plate |
| Thickness Range | 0.5–100 mm | Custom sizes available | ASTM A240 304H dimensions |
| Width / Length | Up to 2500 mm / 12000 mm | Custom fabrication | ASTM A240 304H size options |
| Surface Finish | 2B, No.1, BA, HL | Multiple options | ASTM A240 304H finish |
| Heat Treatment | Annealed | Standard supply condition | ASTM A240 304H annealed |
Chemical Composition
The chemical composition of ASTM A240 Type 304H is designed with a higher carbon range to improve high-temperature strength and creep resistance.
| Element | Content (%) | Standard Limit | Role | Keywords |
|---|---|---|---|---|
| Carbon (C) | 0.04–0.10 | 0.04–0.10 | High-temperature strength & creep resistance | ASTM A240 304H carbon |
| Manganese (Mn) | ≤2.00 | 2.00 max | Deoxidation and strength | ASTM A240 304H manganese |
| Phosphorus (P) | ≤0.045 | 0.045 max | Impurity control | ASTM A240 304H phosphorus |
| Sulfur (S) | ≤0.030 | 0.030 max | Cleanliness | ASTM A240 304H sulfur |
| Silicon (Si) | ≤0.75 | 0.75 max | Oxidation resistance | ASTM A240 304H silicon |
| Chromium (Cr) | 18.00–20.00 | 18.00–20.00 | Corrosion & oxidation resistance | ASTM A240 304H chromium |
| Nickel (Ni) | 8.00–10.50 | 8.00–10.50 | Austenite stability | ASTM A240 304H nickel |
| Nitrogen (N) | ≤0.10 | 0.10 max | Strength contribution | ASTM A240 304H nitrogen |
Mechanical Properties
ASTM A240 Type 304H in the annealed condition provides good room-temperature properties, with significantly improved performance at elevated temperatures compared to standard 304 and 304L.
| Property | Value | Test Method | Keywords |
|---|---|---|---|
| Tensile Strength | ≥515 MPa (75 ksi) | ASTM A370 | ASTM A240 304H tensile |
| Yield Strength (0.2% Offset) | ≥205 MPa (30 ksi) | ASTM A370 | ASTM A240 304H yield |
| Elongation | ≥40% | ASTM A370 | ASTM A240 304H elongation |
| Hardness | ≤201 HB / ≤92 HRB | ASTM E10 / E18 | ASTM A240 304H hardness |
| Density | 8.00 g/cm³ | Standard | ASTM A240 304H density |
ASTM A240 Type 304H Grain Size Requirement
According to ASTM A240/A240M, Type 304H has a mandatory grain size requirement:
The grain size of Type 304H shall be ASTM No. 7 or coarser, as determined in accordance with ASTM E112.
| Item | Requirement |
|---|---|
| Grain Size | ASTM No. 7 or coarser |
| Test Method | ASTM E112 |
| Purpose | To improve high-temperature creep strength and rupture strength |
| Applicable Grades | 304H, 316H, 321H, 347H and other “H” grades |
Notes:
- “Coarser” means larger grains (smaller ASTM grain size number). For example, ASTM No. 5 or No. 6 is coarser than No. 7.
- Standard Type 304 and Type 304L do not have a mandatory grain size requirement. Only the high-temperature “H” grades (such as 304H) require it.
- If the material is dual-certified as 304/304H, it must still meet the grain size requirement of Type 304H (ASTM No. 7 or coarser).
Delivery Conditions
SHH STEEL supplies ASTM A240 Type 304H stainless steel sheet and plate primarily in the annealed condition. Common surface finishes include 2B, No.1, and BA. Protective film can be applied upon request.
| Condition | Description | Keywords |
|---|---|---|
| Annealed | Standard supply condition | ASTM A240 304H annealed |
| Surface Finish | 2B, No.1, BA, HL | ASTM A240 304H surface |
| Protective Film | Available on request | ASTM A240 304H protection |
Tolerances
Dimensional tolerances for ASTM A240 304H sheet and plate comply with ASTM A480. Tighter tolerances are available for special requirements.
| Tolerance Type | Standard | Keywords |
|---|---|---|
| Thickness / Width / Length | ASTM A480 | ASTM A240 304H tolerance |
| Flatness | Per ASTM A480 | ASTM A240 304H flatness |
Weldability
ASTM A240 Type 304H can be welded using standard fusion and resistance welding methods. Due to its higher carbon content, care should be taken to avoid sensitization in certain corrosive environments. Matching or slightly higher alloyed filler metals are typically recommended. Post-weld heat treatment may be required depending on the service conditions.
| Weldability Factor | Recommendation | Keywords |
|---|---|---|
| Preheating | Usually not required | ASTM A240 304H welding |
| Filler Metal | Matching 304H or ER308H | ASTM A240 304H filler |
| Post-Weld Heat Treatment | May be required for critical service | ASTM A240 304H PWHT |
Equivalent Material Grade
ASTM A240 Type 304H has several international equivalents used in high-temperature applications.
| Grade | Standard | Designation | Keywords |
|---|---|---|---|
| Type 304H | ASTM A240 / ASME SA240 | — | ASTM A240 304H equivalent |
| UNS S30409 | Unified Numbering System | S30409 | ASTM A240 304H UNS |
| 1.4948 | EN 10028 / EN 10088 | X6CrNi18-10 | ASTM A240 304H EN |
| SUS304H | JIS G4304 / G4305 | — | ASTM A240 304H JIS / SUS304H |
Supplementary Requirements
Additional testing available for ASTM A240 304H includes elevated temperature tensile testing, creep testing (on request), intergranular corrosion testing, ultrasonic examination, and product analysis.
Applications
Due to its enhanced high-temperature strength and oxidation resistance, ASTM A240 Type 304H stainless steel sheet and plate are widely used in the following applications:
| Application | Typical Use | Keywords |
|---|---|---|
| Boilers & Superheaters | High-temperature pressure parts | ASTM A240 304H boiler |
| Heat Exchangers | Elevated temperature service | ASTM A240 304H heat exchanger |
| Furnace Components | Furnace parts and fixtures | ASTM A240 304H furnace |
| Chemical Processing | High-temperature process equipment | ASTM A240 304H chemical |
| Power Generation | Steam piping and headers | ASTM A240 304H power |
Why Choose SHH STEEL
SHH STEEL is a professional supplier of ASTM A240 Type 304H stainless steel sheet and plate. We offer competitive pricing, flexible custom sizes, reliable quality control, and worldwide delivery. All material is supplied with full Mill Test Certificates.
Advantage | Benefit | Keywords —|—|—|— Full Certification | ASTM A240 / ASME SA240 + MTC 3.1 | ASTM A240 304H certified Flexible Supply | Sheet & Plate, custom sizes | ASTM A240 304H custom Global Experience | Export to 50+ countries | ASTM A240 304H trusted supplier
FAQ
- What is the main difference between ASTM A240 304, 304L, and 304H?The key difference is carbon content. Type 304 has C ≤0.08%, Type 304L has C ≤0.03% (best for welded corrosive service), and ASTM A240 Type 304H has C 0.04–0.10% for improved high-temperature strength and creep resistance.
- When should I choose ASTM A240 Type 304H?Choose ASTM A240 304H when the application involves continuous service at elevated temperatures (typically above 500°C), such as in boilers, heat exchangers, or furnace components.
- Is ASTM A240 304H the same as SS304H or SUS304H?Yes. ASTM A240 Type 304H, SS304H, SUS304H, and UNS S30409 refer to the same high-carbon austenitic stainless steel grade.
- What is the density of ASTM A240 Type 304H?The density of ASTM A240 Type 304H is 7.93 g/cm³
- Can ASTM A240 304H be dual-certified with 304?In some cases, material can meet both 304 and 304H requirements if the carbon content falls within the overlapping range and other properties are satisfied. Please contact us for dual-certification options.
Conclusion
SHH STEEL’s ASTM A240 Type 304H Stainless Steel Sheet and Plate deliver superior high-temperature strength, creep resistance, and oxidation resistance for demanding elevated-temperature applications. With strict quality control, flexible sizing, and professional global export service, we provide reliable 304H stainless steel plate and 304H stainless steel sheet solutions to customers worldwide. Contact SHH STEEL today for your ASTM A240 304H requirements.
Keywords of ASTM A240 Type 304H
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