ASME SA240 304 Stainless Steel Plate | SA240 Type 304
What is ASME SA240 304 Stainless Steel Plate?
As a professional stainless steel plate supplier and China Mill-Direct Supply / Mill Direct Exporter, SHH STEEL is pleased to present ASME SA240 304 Stainless Steel Plate, also known as SA240 Type 304.
ASME SA240 is the American Society of Mechanical Engineers specification covering chromium and chromium-nickel stainless steel plate, sheet, and strip for pressure vessels and general applications. SA240 Type 304 is essentially identical in chemistry and mechanical properties to ASTM A240 Type 304, and is the most commonly specified austenitic stainless steel grade worldwide. It contains nominally 18% chromium and 8% nickel (the classic 18-8 composition), delivering an outstanding balance of corrosion resistance, formability, weldability, toughness and cost-effectiveness.
SHH STEEL supplies ASME SA240 304 stainless steel plate as true Mill Direct Supply, sourcing directly from major Chinese stainless steel producers. This model allows us to offer competitive mill pricing, consistent quality, shorter lead times and complete traceability. We provide thicknesses from 0.4 mm up to 100 mm (and thicker on request), widths up to 2000–3000 mm, and lengths up to 12000 mm or custom cut-to-length. Both hot-rolled and cold-rolled conditions are available, together with a full range of surface finishes.
ASME SA240 304 is non-magnetic in the annealed condition, possesses excellent toughness even at cryogenic temperatures, and can be readily formed, welded and fabricated. It remains the default choice for the majority of stainless steel plate applications unless higher corrosion resistance, higher strength or special high-temperature performance is required.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Primary Standard | ASME SA240 / SA240M | Full compliance |
| Steel Grade | Type 304 (UNS S30400) | Confirmed |
| Product Form | Plate, Sheet, Coil | Available |
| Delivery Condition | Annealed | Standard |
| Thickness Range | 0.4 mm – 100 mm (thicker available) | Custom sizes supported |
| Width | Up to 2000–3000 mm | Available |
| Length | Up to 12000 mm or cut-to-length | Available |
| Surface Finish | No.1, 2B, BA, No.4, HL, Polished | Available |
| Certification | EN 10204 3.1 / ASME Mill Test Certificate | Available |
Chemical Composition
Chemical composition of ASME SA240 Type 304 (Heat Analysis):
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Silicon (Si) | ≤ 0.75 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 18.00 – 20.00 |
| Nickel (Ni) | 8.00 – 10.50 |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
The balanced 18% chromium + 8% nickel composition forms a stable passive chromium-oxide film that provides excellent resistance to a wide range of atmospheric, aqueous and chemical environments. Carbon is limited to 0.08% maximum to maintain good corrosion performance while still allowing the grade to be used in the majority of welded constructions. For heavily welded structures or applications where intergranular corrosion is a concern, the low-carbon version SA240 Type 304L is usually preferred.
Mechanical Properties
Mechanical properties of ASME SA240 Type 304 in the annealed condition:
| Property | Value |
|---|---|
| Tensile Strength | ≥ 515 MPa (75 ksi) |
| Yield Strength (0.2%) | ≥ 205 MPa (30 ksi) |
| Elongation (in 50 mm) | ≥ 40% |
| Hardness | ≤ 201 HB / ≤ 92 HRB |
| Impact Toughness | Excellent down to cryogenic temperatures |
ASME SA240 304 retains outstanding ductility and toughness even at very low temperatures, making it suitable for cryogenic service. Cold working significantly increases strength and hardness, although ductility decreases. The grade can be readily formed by bending, drawing, spinning and roll forming.
Density: 7.93 g/cm³ Melting Range: 1400–1450°C Magnetic Permeability: Non-magnetic in the annealed condition (may become slightly magnetic after heavy cold work)
Corrosion Resistance
ASME SA240 304 offers excellent corrosion resistance in a wide variety of environments, including:
- Atmospheric exposure (rural, urban and mild industrial)
- Fresh water and many mild chemical solutions
- Food processing environments
- Oxidizing acids (such as nitric acid)
- Organic acids and compounds
It has good resistance to intergranular corrosion in the annealed condition. However, when the material is heated in the sensitization temperature range (approximately 450–850°C) and then exposed to corrosive media, chromium carbides may precipitate at grain boundaries. In such cases, the low-carbon grade SA240 304L or a stabilized grade (321 or 347) is recommended.
ASME SA240 304 is not recommended for continuous service in strong reducing acids or in environments with high chloride concentrations at elevated temperatures, where pitting or stress corrosion cracking may occur. For these more aggressive conditions, molybdenum-bearing grades such as 316L, 317L or higher alloys are preferred.
Weldability
ASME SA240 304 possesses excellent weldability by all standard fusion and resistance welding methods. Matching or slightly over-alloyed filler metals (E308 / ER308 or E308L / ER308L) are commonly used.
Key welding considerations:
- Low carbon versions (304L) or stabilized grades are preferred for heavy multi-pass welds to minimize the risk of intergranular corrosion.
- Post-weld heat treatment is generally not required for thin sections.
- Proper cleaning before and after welding is essential to maintain corrosion resistance.
- The grade can be welded to other austenitic stainless steels and to carbon steels using appropriate procedures and filler metals.
ASME SA240 304 Heat Treatment
ASME SA240 304 is supplied in the solution-annealed condition. The recommended annealing temperature range is 1010–1120°C followed by rapid cooling (water quench or air cool depending on thickness). Annealing restores corrosion resistance, ductility and non-magnetic properties after cold working or welding.
Stress relieving can be performed at 200–400°C if required, but care must be taken to avoid the sensitization range.
Surface Finishes
| Finish | Description | Typical Use |
|---|---|---|
| No.1 | Hot-rolled, annealed and pickled | Industrial and pressure vessel applications |
| 2B | Cold-rolled, annealed, pickled, skin-passed | General fabrication, most common finish |
| BA | Bright Annealed | Decorative, kitchen, clean applications |
| No.4 | Brushed (satin) finish | Architectural, elevators, kitchen equipment |
| HL | Hairline finish | Decorative panels |
| Polished | Mirror or custom polish | High-end decorative and sanitary use |
SHH STEEL can supply ASME SA240 304 in all standard finishes according to project requirements.
Tolerances
Dimensional tolerances for ASME SA240 304 stainless steel plate follow the requirements of ASME SA240 / ASTM A480. Tighter tolerances can be provided upon request. Flatness, thickness, width and length tolerances are carefully controlled during production and final inspection.
Equivalent Material Grades
| Grade / Designation | Standard | Notes |
|---|---|---|
| SA240 Type 304 | ASME SA240 | — |
| A240 Type 304 | ASTM A240 | Essentially identical |
| SUS304 | JIS G4305 / G4304 | Japanese equivalent |
| 1.4301 / X5CrNi18-10 | EN 10088-2 | European equivalent |
| 06Cr19Ni10 | GB/T 3280 | Chinese equivalent |
| UNS S30400 | — | Unified Numbering System |
Related grades that are frequently compared or used together with ASME SA240 304 include:
- astm a240 type 304l stainless steel sheet plate — low-carbon version for superior weldability
- astm a240 type 316 stainless steel sheet plate and astm a240 type 316l stainless steel sheet plate — higher pitting resistance
- astm a240 type 321 stainless steel sheet plate and astm a240 type 347 stainless steel sheet plate — stabilized grades for high-temperature service
- jis g4305 sus430 steel plate — lower-cost ferritic alternative for milder environments
Applications
| Industry / Sector | Typical Components / Equipment |
|---|---|
| Food & Beverage | Tanks, vessels, piping, processing equipment, sinks |
| Chemical & Petrochemical | Storage tanks, reactors (mild service), piping |
| Pharmaceutical | Clean equipment, vessels, piping systems |
| Architectural & Construction | Cladding, roofing, elevators, handrails, decorative panels |
| Pressure Vessels | ASME stamped vessels and components |
| Heat Exchangers | Shells, channels, tubesheets (moderate duty) |
| Water Treatment | Tanks, piping, structural components |
| Automotive & Transportation | Exhaust components, trim, structural parts |
| General Fabrication | Frames, enclosures, machinery components |
Because of its versatility, ASME SA240 304 remains the first material considered for the majority of stainless steel plate projects unless special corrosion, temperature or strength requirements dictate a higher-alloy grade.
Why Choose SHH STEEL
SHH STEEL is a China Mill-Direct Supply and Mill Direct Exporter of stainless steel plate. We maintain long-term strategic cooperation with major Chinese stainless steel mills and act as a first-level supply partner. This direct mill supply model enables us to offer:
- Competitive mill-direct pricing
- Stable and consistent quality
- Shorter lead times
- Full Mill Test Certificates (EN 10204 3.1 / ASME)
- Complete traceability
- Flexible processing services (cutting, surface finishing, packaging)
- Professional export documentation and worldwide logistics support
Customers worldwide rely on SHH STEEL for reliable supply of ASME SA240 304 stainless steel plate for both standard and project-based requirements.
FAQ
- What is the difference between ASME SA240 304 and ASTM A240 304?The chemical composition and mechanical properties are essentially identical. ASME SA240 is the version adopted for use under the ASME Boiler and Pressure Vessel Code, while ASTM A240 is the general materials specification. In practice, material certified to ASME SA240 is fully acceptable for most ASTM A240 applications and vice versa when dual certification is provided.
- When should I choose SA240 304L instead of SA240 304?Choose 304L when the material will undergo significant welding, especially heavy multi-pass welds, or when the service environment may promote intergranular corrosion. The lower carbon content of 304L greatly reduces the risk of sensitization.
- Is ASME SA240 304 magnetic?In the annealed condition it is non-magnetic. After heavy cold working it may become slightly magnetic.
- What surface finishes are available?We regularly supply No.1, 2B, BA, No.4, HL and polished finishes according to customer requirements.
- Can SHH STEEL provide dual-certified ASME SA240 / ASTM A240 material?Yes. Dual certification is commonly available and frequently requested by our customers.
- What is the standard density of SA240 304?7.93 g/cm³.
Conclusion
ASME SA240 304 Stainless Steel Plate (SA240 Type 304) remains the most versatile and widely used austenitic stainless steel plate in the world. It offers an excellent combination of corrosion resistance, formability, weldability, toughness and economy. As a professional China Mill-Direct Supply and Mill Direct Exporter, SHH STEEL provides reliable material, competitive pricing and complete technical support for this grade.
Whether you require standard 2B finish plate for general fabrication or specially finished material for architectural or sanitary applications, SHH STEEL is ready to support your project.
Contact SHH STEEL today for stock availability, processing options, dual certification or a competitive quotation.
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