ASTM A240 Type 409 Stainless Steel Sheet & Plate
ASTM A240 Type 409 Stainless Steel Sheet & Plate | 409 / UNS S40900
As a professional stainless steel supplier, SHH STEEL is pleased to present ASTM A240 Type 409 Stainless Steel Sheet and Plate. Also known as UNS S40900, this grade is a titanium-stabilized ferritic stainless steel containing 10.5–11.75% chromium.
Type 409 provides a cost-effective combination of good high-temperature oxidation resistance, formability and weldability. It is one of the most widely used stainless steels for automotive exhaust systems and other applications requiring moderate corrosion resistance at elevated temperatures. SHH STEEL supplies ASTM A240 Type 409 in both sheet and plate forms, covering thicknesses from 0.4 mm to 80 mm, with widths up to 1500–2000 mm and lengths up to 12000 mm. Custom sizes and surface finishes are available.
The material is typically delivered in the annealed condition with full Mill Test Certificates (EN 10204 3.1). Whether for thin sheet fabrication or heavier plate applications, SHH STEEL provides consistent quality for automotive, exhaust and industrial projects worldwide.
Material Specification
ASTM A240 Type 409 stainless steel sheet and plate are manufactured in accordance with ASTM A240/A240M and ASME SA-240.
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Primary Standard | ASTM A240 / ASME SA-240 Type 409 | Full compliance |
| UNS Designation | S40900 | Confirmed |
| Product Form | Sheet and Plate | Both available |
| Thickness Range | 0.4 mm – 80 mm | Custom sizes available |
| Width / Length | Up to 1500–2000 mm / 12000 mm | Custom fabrication supported |
| Surface Finish | 2B, BA, No.1 | Multiple options |
| Heat Treatment Condition | Annealed | Standard supply condition |
| Certification | EN 10204 3.1 / 3.2 | Available |
Chemical Composition
The chemical composition of ASTM A240 Type 409 is designed for good high-temperature performance and formability through titanium stabilization.
| Element | Content (%) | Standard Limit | Role |
|---|---|---|---|
| Carbon (C) | ≤ 0.08 | 0.08 max | Strength and corrosion balance |
| Manganese (Mn) | ≤ 1.00 | 1.00 max | Deoxidation and strength |
| Phosphorus (P) | ≤ 0.045 | 0.045 max | Impurity control |
| Sulfur (S) | ≤ 0.030 – 0.045 | 0.045 max | Cleanliness |
| Silicon (Si) | ≤ 1.00 | 1.00 max | Deoxidation and oxidation resistance |
| Chromium (Cr) | 10.5 – 11.75 | 10.5 – 11.75 | Corrosion and oxidation resistance |
| Nickel (Ni) | ≤ 0.50 | 0.50 max | — |
| Titanium (Ti) | 6×C min – 0.75 max | 6×C min – 0.75 max | Stabilization against intergranular corrosion |
Mechanical Properties
In the annealed condition, ASTM A240 Type 409 provides good formability and moderate strength.
| Property | Value | Test Method |
|---|---|---|
| Tensile Strength | ≥ 380 – 450 MPa | ASTM A370 |
| Yield Strength (0.2% Offset) | ≥ 170 – 240 MPa | ASTM A370 |
| Elongation in 50 mm | ≥ 20 – 25% | ASTM A370 |
| Hardness | ≤ 95 HRB / ≤ 207 HB | ASTM E18/E10 |
| Density | 7.7 – 7.8 g/cm³ | — |
Delivery Conditions
SHH STEEL supplies ASTM A240 Type 409 primarily in the annealed condition. Detailed capabilities by surface finish are as follows:
2B Finish (Cold-rolled, annealed, pickled and skin-passed)
- Typical thickness range: 0.4 mm – 3.0 mm (up to 6.0 mm possible)
- Maximum width: up to 1500–2000 mm
- Most common finish for exhaust system components and general fabrication.
BA (Bright Annealed)
- Available in thinner gauges for specific applications.
No.1 Finish (Hot-rolled, annealed and pickled)
- Typical thickness range: 3.0 mm – 80 mm
- Standard finish for heavier plates.
Protective PVC film can be applied on one or both sides. Precision cutting (plasma, laser or waterjet) and closer dimensional tolerances are available upon request.
Tolerances
Dimensional tolerances for ASTM A240 Type 409 sheet and plate follow ASTM A480/A480M.
- Thickness tolerances vary by product form and thickness.
- Width tolerance is typically +6 mm / 0 mm or better for cold-rolled sheet.
- Length tolerance for cut-to-length material is normally +10 mm / 0 mm.
- Flatness is controlled according to ASTM A480; improved flatness can be supplied for precision fabrication.
- Edge conditions include mill edge, slit edge, sheared edge or plasma/laser cut edge according to customer preference.
Tighter tolerances can be arranged for special projects.
Weldability
ASTM A240 Type 409 can be welded by common fusion processes such as GTAW (TIG), GMAW (MIG) and SMAW. The titanium stabilization helps reduce the risk of intergranular corrosion in the heat-affected zone.
Matching or suitable ferritic filler metals are commonly used. Heat input should be controlled to minimize grain growth. Preheating is generally not required for thin sections. Proper cleaning after welding is recommended to maintain corrosion resistance. For critical welded applications requiring better intergranular corrosion resistance, the lower-carbon Type 409L is often preferred.
Equivalent Material Grades
| Grade | Standard | Designation |
|---|---|---|
| Type 409 | ASTM A240 / ASME SA-240 | — |
| UNS S40900 | Unified Numbering System | — |
| 1.4512 | EN 10088 | X2CrTi12 / X6CrTi12 |
| SUH409 / SUS409 | JIS | — |
| Related Chinese grades | GB/T series | 11% Cr Ti-stabilized ferritic types |
| X6CrTi12 | DIN / EN | — |
ASTM A240 Type 409 Applications
ASTM A240 Type 409 is widely used in applications requiring good high-temperature oxidation resistance, formability and cost efficiency. Typical applications are shown below with relevant keywords:
| Application Area | Typical Components / Uses (Keywords) |
|---|---|
| Automotive Exhaust Systems | Exhaust pipes, mufflers, catalytic converter shells, manifolds – A240 409 Automotive Exhaust |
| Heat Exchangers | Heat exchanger components – A240 409 Heat Exchanger |
| Agricultural & Construction Equipment | Exhaust and heat-resistant parts – A240 409 Agricultural |
| Residential Heating | Furnace parts, boiler components – A240 409 Heating |
| General Fabrication | Formed and welded parts in mildly corrosive or high-temperature environments – A240 409 Fabrication |
| Industrial Components | Cost-effective heat-resistant parts – A240 409 Industrial |
Why Choose SHH STEEL
SHH STEEL maintains long-term strategic cooperation with major Chinese stainless steel mills and acts as a first-level (primary) agent for these mills. This direct partnership enables us to offer competitive pricing advantages, faster delivery times and consistent quality assurance that many intermediate traders cannot match.
All ASTM A240 Type 409 material is sourced from reputable Chinese mills under strict quality control, supplied with complete Mill Test Certificates, and supported by our professional export team. Customers benefit from reliable supply, short lead times, technical support and cost-effective solutions for automotive exhaust and industrial applications worldwide.
FAQ
- What is the main difference between Type 409 and Type 409L?Type 409 allows higher carbon content (≤ 0.08%) compared with Type 409L (≤ 0.03%). Type 409L offers better weldability and improved resistance to intergranular corrosion due to its lower carbon content, while Type 409 remains a cost-effective choice for many exhaust applications.
- Is Type 409 magnetic?Yes. Type 409 is a ferritic stainless steel and is magnetic.
- What is the UNS designation for ASTM A240 Type 409?UNS S40900.
- Why is Type 409 widely used in automotive exhaust systems?It provides a good balance of high-temperature oxidation resistance, formability, weldability and low cost, making it one of the most economical stainless steels suitable for exhaust components.
- What is the density of ASTM A240 Type 409?Approximately 7.7 – 7.8 g/cm³.
Conclusion
ASTM A240 Type 409 (UNS S40900) Stainless Steel Sheet and Plate from SHH STEEL provide an economical combination of good high-temperature oxidation resistance, formability and titanium stabilization. With strict quality control, flexible sizing options, competitive pricing through direct mill partnerships and professional global export service, we deliver trusted solutions for automotive exhaust systems and industrial applications worldwide.
Contact SHH STEEL today for your ASTM A240 Type 409 (UNS S40900) requirements.
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