ASME SA240 409 Stainless Steel Plate | SA240 Type 409
What is ASME SA240 409 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 409 Stainless Steel Plate, also known as SA240 Type 409.
ASME SA240 Type 409 is a low-cost titanium-stabilized ferritic stainless steel containing approximately 10.5–11.75% chromium. The titanium addition stabilizes carbon and nitrogen, improving weldability and resistance to intergranular corrosion. Type 409 provides good resistance to oxidation and scaling at elevated temperatures (typically up to 700–800°C in continuous service), combined with excellent formability and a very competitive cost.
It is the most widely used stainless steel in automotive exhaust systems worldwide, including mufflers, catalytic converter shells, exhaust pipes and related components. It is also used in heat exchangers, furnace parts and other applications where moderate high-temperature oxidation resistance is required at the lowest possible cost.
SHH STEEL supplies ASME SA240 409 as true Mill Direct Supply, sourcing directly from major Chinese stainless steel mills. This model delivers competitive mill pricing, consistent quality, full heat traceability and shorter lead times. We offer a practical dimensional range in both coil and plate form, with surface finishes suitable for automotive and industrial applications.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Primary Standard | ASME SA240 / SA240M | Full compliance |
| Steel Grade | Type 409 (UNS S40900) | Confirmed |
| Product Form | Plate, Sheet, Coil | Available |
| Delivery Condition | Annealed | Standard |
| Thickness Range | 0.4 mm – 6.0 mm (thicker available on request) | Custom sizes supported |
| Width | Up to 1500 mm (wider on request) | Available |
| Length | Coil or cut-to-length | Available |
| Surface Finish | 2B, No.1, and others on request | Available |
| Certification | EN 10204 3.1 / ASME Mill Test Certificate | Available |
Chemical Composition
Heat Analysis (Ladle Analysis) according to ASME SA240 Type 409:
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 10.50 – 11.75 |
| Nickel (Ni) | ≤ 0.50 |
| Titanium (Ti) | ≥ 6 × C% and ≤ 0.75 |
| Iron (Fe) | Balance |
Product Analysis (typical permissible variations):
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 10.40 – 11.85 |
| Nickel (Ni) | ≤ 0.50 |
| Titanium (Ti) | ≥ 6 × C% and ≤ 0.75 |
The titanium stabilization (minimum Ti = 6 × C%) is the key feature that improves weldability and prevents intergranular corrosion. The relatively low chromium content keeps the grade economical while still providing useful oxidation resistance for exhaust and heat applications.
Mechanical Properties
Annealed Condition (typical)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 380 MPa (55 ksi) |
| Yield Strength (0.2%) | ≥ 170 MPa (25 ksi) |
| Elongation (in 50 mm) | ≥ 20% |
| Hardness | ≤ 179 HB |
Physical Properties
- Density: approximately 7.75 g/cm³
- Magnetic: Magnetic in all conditions
- Melting Range: approximately 1480–1530°C
Type 409 cannot be hardened by heat treatment. It offers excellent formability, which is critical for the complex shapes used in automotive exhaust systems.
Material Comparison
| Grade | Structure | Cr Content | Key Advantage | Typical Preference |
|---|---|---|---|---|
| SA240 Type 409 | Ferritic | 10.5–11.75% | Lowest cost + good oxidation resistance | Automotive exhaust systems |
| SA240 Type 409L | Ferritic | Similar + lower C | Improved weldability & corrosion | Higher-performance exhaust |
| SA240 Type 439 | Ferritic | 17–19% + Ti | Better corrosion & oxidation resistance | More demanding exhaust / heat systems |
| SA240 Type 430 | Ferritic | 16–18% | Better general corrosion resistance | Appliances, trim, general use |
| SA240 Type 304 | Austenitic | 18–20% | Excellent corrosion resistance | General corrosive service |
ASME SA240 409 is the most economical stainless steel for high-temperature oxidation resistance in automotive exhaust applications. When better corrosion resistance or higher temperature capability is needed, astm a240 type 439 stainless steel sheet plate or astm a240 type 441 stainless steel sheet plate are common upgrades. For general corrosion resistance, astm a240 type 430 stainless steel sheet plate is preferred.
Corrosion Resistance
ASME SA240 Type 409 offers moderate corrosion resistance in atmospheric and mild environments, with its main strength being resistance to high-temperature oxidation and scaling. It performs well in the hot, dry, and condensate conditions typical of automotive exhaust systems.
It is not suitable for severe chloride environments, strong acids, or continuous exposure to seawater. In such cases, higher-alloy ferritic or austenitic grades should be selected.
Weldability
ASME SA240 Type 409 has good weldability for a ferritic stainless steel due to titanium stabilization. The risk of intergranular corrosion is low.
Low heat input is recommended to minimize grain growth in the heat-affected zone. Matching or suitable ferritic/austenitic filler metals can be used. It is readily welded by resistance, MIG, TIG and other common methods used in automotive production.
Heat Treatment
Type 409 is a ferritic stainless steel and cannot be hardened by quenching and tempering.
Annealing
- Temperature: typically 750 – 850°C
- Cooling: Air cool
Annealing is used to relieve stresses after cold working or welding and to restore ductility. Excessive time at high temperature should be avoided to limit grain growth.
Surface Finishes
| Finish | Description | Typical Use / Keywords |
|---|---|---|
| 2B | Cold-rolled, annealed, pickled, skin-passed | SA240 409 2B – most common for automotive exhaust and general use |
| No.1 | Hot-rolled, annealed and pickled | SA240 409 No.1 – industrial plate |
| Special | Bright or custom finishes | SA240 409 Special – on request |
SHH STEEL regularly supplies ASME SA240 409 in 2B finish (especially in coil form for automotive applications) and No.1 finish for plate.
Tolerances
Dimensional tolerances for ASME SA240 409 Stainless Steel Plate conform to ASME SA240 and the general requirements of ASTM A480.
Typical available size range for SA240 409 plate/sheet/coil:
- Thickness: 0.4 mm – 6.0 mm (thicker plates available on request)
- Width: up to 1500 mm (wider on request)
- Form: Coil or cut-to-length plate
Thickness, width and flatness tolerances are controlled within standard limits. Tighter tolerances for SA240 409 can be arranged for specific automotive or project needs. SHH STEEL provides precise dimensional control for both coil and plate products.
Equivalent Material Grades
| Grade / Designation | Standard | Notes |
|---|---|---|
| SA240 Type 409 | ASME SA240 | — |
| A240 Type 409 | ASTM A240 | Essentially identical |
| UNS S40900 | — | Unified Numbering System |
| 1.4512 / X2CrTi12 | EN 10088-2 | European equivalent |
| SUS409 | JIS G4305 | Japanese equivalent |
| 06Cr11Ti / related | GB/T | Chinese equivalent |
Related grades frequently evaluated with ASME SA240 409 include astm a240 type 409l stainless steel sheet plate, astm a240 type 439 stainless steel sheet plate, astm a240 type 430 stainless steel sheet plate, and astm a240 type 441 stainless steel sheet plate.
Applications
ASME SA240 Type 409 is the dominant material for automotive exhaust systems. Typical applications of SA240 409 include:
| Industry / Sector | Typical Components / Equipment (with keywords) |
|---|---|
| Automotive Exhaust | SA240 409 mufflers, exhaust pipes, catalytic converter shells, resonators |
| Heat Exchangers | SA240 409 heat exchanger components in mild high-temperature service |
| Furnace & Heat Treatment | SA240 409 furnace parts and heat-resistant components |
| Agricultural & Construction Equipment | SA240 409 exhaust and heat-related parts |
| General Fabrication | SA240 409 formed and welded high-temperature components |
| Industrial Exhaust Systems | SA240 409 ducting and exhaust components |
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 supply ASME SA240 Type 409 with the following advantages:
- Competitive mill-direct pricing
- Consistent quality and complete heat traceability
- Full Mill Test Certificates (EN 10204 3.1 /3.2 ASME)
- Coil and plate supply with flexible dimensions
- Surface finishes including SA240 409 2B and SA240 409 No.1
- Technical support for automotive and high-temperature applications
- Reliable worldwide logistics and export documentation
Conclusion
- What is the main advantage of SA240 409?Type 409 offers the best combination of high-temperature oxidation resistance, formability, weldability and low cost among standard stainless steels, making it ideal for automotive exhaust systems. SHH STEEL is a major supplier of 409 for this application.
- Is ASME SA240 409 magnetic?Yes, Type 409 is magnetic in all conditions. SHH STEEL supplies material that meets this characteristic.
- Can SA240 409 be hardened by heat treatment?No. As a ferritic stainless steel, it cannot be hardened by quenching and tempering. SHH STEEL supplies material in the annealed condition as standard.
- What is the difference between 409 and 409L?Type 409L has lower carbon and tighter residual controls for improved weldability and corrosion resistance. SHH STEEL can supply both grades according to customer requirements.
- What is the density of SA240 Type 409?Approximately 7.75 g/cm³. SHH STEEL provides material certificates confirming physical and mechanical properties.
- Can SHH STEEL supply dual-certified ASME SA240 / ASTM A240 Type 409?Yes, SHH STEEL commonly supplies dual-certified ASME SA240 / ASTM A240 Type 409 material.
Conclusion
ASME SA240 409 Stainless Steel Plate (SA240 Type 409) is a titanium-stabilized ferritic stainless steel that delivers reliable high-temperature oxidation resistance, excellent formability and outstanding economy. It remains the global standard material for automotive exhaust systems and many other cost-sensitive high-temperature applications.
As a professional China Mill-Direct Supply and Mill Direct Exporter, SHH STEEL provides high-quality ASME SA240 Type 409 plate and coil with competitive pricing, full certification and complete technical support.
Contact SHH STEEL today for stock availability, coil or plate options, surface finishes (including SA240 409 2B and SA240 409 No.1), or a competitive quotation.
ASME SA240 409 Stainless Steel Plate, SA240 Type 409, SA240 409, ASME SA240 Type 409, 409 stainless steel plate, SA240 409 supplier
Quality Steel Needed? Inquire for Offers
Related Products
