ASTM A240 Type 439 Stainless Steel Sheet & Plate
ASTM A240 Type 439 Stainless Steel Sheet & Plate | 439 / UNS S43035
As a professional stainless steel supplier, SHH STEEL is pleased to present ASTM A240 Type 439 Stainless Steel Sheet and Plate. Also known as UNS S43035, this grade is a titanium-stabilized ferritic stainless steel containing 17.0–19.0% chromium.
Type 439 was developed as an improved version of Type 430. The addition of titanium (minimum 0.20% + 4×(C+N)) stabilizes carbon and nitrogen, providing excellent resistance to intergranular corrosion after welding or exposure to sensitization temperatures. It also offers better oxidation resistance and formability than many other ferritic grades. SHH STEEL supplies ASTM A240 Type 439 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 systems, heat exchangers and industrial projects worldwide.
Material Specification
ASTM A240 Type 439 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 439 | Full compliance |
| UNS Designation | S43035 | 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, HL, 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 439 is carefully controlled with titanium stabilization for superior resistance to intergranular corrosion.
| Element | Content (%) | Standard Limit | Role |
|---|---|---|---|
| Carbon (C) | ≤ 0.030 | 0.030 max | Low carbon for good weldability |
| Manganese (Mn) | ≤ 1.00 | 1.00 max | Deoxidation and strength |
| Phosphorus (P) | ≤ 0.040 | 0.040 max | Impurity control |
| Sulfur (S) | ≤ 0.030 | 0.030 max | Cleanliness |
| Silicon (Si) | ≤ 1.00 | 1.00 max | Deoxidation |
| Chromium (Cr) | 17.0 – 19.0 | 17.0 – 19.0 | Corrosion and oxidation resistance |
| Nickel (Ni) | ≤ 0.50 | 0.50 max | — |
| Nitrogen (N) | ≤ 0.030 | 0.030 max | Controlled |
| Titanium (Ti) | 0.20+4(C+N) min – 1.10 max | 0.20+4(C+N) min – 1.10 max | Stabilization against intergranular corrosion |
| Aluminum (Al) | ≤ 0.15 | 0.15 max | Optional |
Mechanical Properties
In the annealed condition, ASTM A240 Type 439 provides good strength and excellent formability.
| Property | Value | Test Method |
|---|---|---|
| Tensile Strength | ≥ 415 MPa (60 ksi) | ASTM A370 |
| Yield Strength (0.2% Offset) | ≥ 205 MPa (30 ksi) | ASTM A370 |
| Elongation in 50 mm | ≥ 22% | ASTM A370 |
| Hardness | ≤ 89 HRB / ≤ 183 HB | ASTM E18/E10 |
| Density | 7.70 g/cm³ | — |
Delivery Conditions
SHH STEEL supplies ASTM A240 Type 439 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 general fabrication and formed components.
BA (Bright Annealed)
- Available in thinner gauges for applications requiring a brighter surface.
No.1 Finish (Hot-rolled, annealed and pickled)
- Typical thickness range: 3.0 mm – 80 mm
- Standard finish for heavier plates.
HL (Hairline)
- Available on request for decorative or specific functional requirements.
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 439 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 439 offers good weldability for a ferritic stainless steel due to its low carbon content and titanium stabilization. It can be welded by common fusion processes such as GTAW (TIG), GMAW (MIG) and SMAW.
The titanium stabilization effectively prevents intergranular corrosion in the heat-affected zone, making post-weld annealing unnecessary in most applications. Matching or suitable ferritic/austenitic filler metals may be used depending on service requirements. 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.
Equivalent Material Grades
| Grade | Standard | Designation |
|---|---|---|
| Type 439 | ASTM A240 / ASME SA-240 | — |
| UNS S43035 | Unified Numbering System | — |
| 1.4510 | EN 10088 | X3CrTi17 |
| SUS430LX | JIS | — |
| Related Chinese grades | GB/T series | Ti-stabilized 17–19% Cr ferritic types |
| X3CrTi17 | DIN / EN | — |
Applications
ASTM A240 Type 439 is widely used where improved resistance to intergranular corrosion, good oxidation resistance and formability are required. Typical applications are shown below with relevant keywords:
| Application Area | Typical Components / Uses (Keywords) |
|---|---|
| Automotive Exhaust Systems | Manifolds, exhaust pipes, catalytic converter shells – A240 439 Automotive Exhaust |
| Heat Exchangers | Heat exchanger tubes and plates – A240 439 Heat Exchanger |
| Residential & Commercial Appliances | Water heaters, furnace parts – A240 439 Appliances |
| Chemical & Process Equipment | Components in mildly corrosive environments – A240 439 Chemical |
| Architectural & Decorative | Exterior and interior panels – A240 439 Architectural |
| General Fabrication | Welded and formed parts requiring good corrosion resistance – A240 439 Fabrication |
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 439 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, heat exchanger and industrial applications worldwide.
FAQ
- What is the main difference between Type 430 and Type 439?Type 439 is titanium-stabilized with lower carbon content (≤ 0.030%) compared with Type 430 (C ≤ 0.12%). The titanium addition provides excellent resistance to intergranular corrosion after welding, better oxidation resistance, and improved performance in applications involving thermal cycling or welded constructions. Type 430 is more economical for general non-welded or mildly corrosive uses.
- Why is titanium added to Type 439?Titanium combines preferentially with carbon and nitrogen to form stable titanium carbides/nitrides. This prevents the formation of chromium carbides at grain boundaries during welding or exposure to temperatures in the sensitization range, thereby maintaining corrosion resistance in the heat-affected zone.
- What is the UNS designation for ASTM A240 Type 439?UNS S43035.
- What is the density of ASTM A240 Type 439?Approximately 7.70 g/cm³.
- Is Type 439 suitable for automotive exhaust systems?Yes. Type 439 is widely used in automotive exhaust components such as manifolds and pipes because of its good high-temperature oxidation resistance, formability, and resistance to intergranular corrosion after welding. It outperforms Type 409 in more demanding exhaust environments.
- Can Type 439 replace Type 304 in some applications?In certain mildly corrosive or high-temperature oxidation environments where chloride stress corrosion cracking is not a primary concern, Type 439 can be a more cost-effective alternative to Type 304, especially when magnetic properties or lower thermal expansion are advantageous. However, Type 304 generally offers better overall corrosion resistance in chloride-containing media.
Conclusion
ASTM A240 Type 439 (UNS S43035) Stainless Steel Sheet and Plate from SHH STEEL provide excellent resistance to intergranular corrosion through titanium stabilization, combined with good oxidation resistance and formability. 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, heat exchangers and industrial applications worldwide.
Contact SHH STEEL today for your ASTM A240 Type 439 (UNS S43035) requirements.
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