ASTM A240 Type 309S Stainless Steel Sheet & Plate
What is ASTM A240 Type 309S Stainless Steel Sheet & Plate?
As a professional stainless steel plate and sheet supplier, SHH STEEL is pleased to present ASTM A240 Type 309S Stainless Steel Sheet and Plate. Also known as UNS S30908 or SS309S, this grade is a low-carbon version of Type 309 designed for improved weldability and resistance to intergranular corrosion while maintaining outstanding performance at elevated temperatures.
Type 309S contains approximately 23% chromium and 13% nickel, providing superior oxidation resistance in continuous service up to about 1000–1035°C and intermittent service up to 1095°C. The reduced carbon content (maximum 0.08%) makes it more suitable for welded constructions compared with standard Type 309.
SHH STEEL supplies ASTM A240 Type 309S in both sheet and plate forms, covering a wide thickness range from thin cold-rolled sheets to heavy hot-rolled plates. The material is typically delivered in the solution-annealed condition with excellent high-temperature strength, oxidation resistance, and fabricability. Full Mill Test Certificates (EN 10204 3.1) are provided with every order.
Material Specification
ASTM A240 Type 309S stainless steel sheet and plate are manufactured in accordance with ASTM A240/A240M and the corresponding ASME SA-240 specification. This standard covers chromium and chromium-nickel stainless steel plate, sheet, and strip for pressure vessels and general applications, including high-temperature service.
SHH STEEL offers the material in the annealed condition with common surface finishes such as 2B, No.1, BA, and HL. Thicknesses range from 0.5 mm to 100 mm. Widths up to 2500 mm and lengths up to 12000 mm are available, with custom dimensions supported.
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Primary Standard | ASTM A240 / ASME SA-240 Type 309S | Full compliance |
| Product Form | Sheet and Plate | Both available |
| Thickness Range | 0.5 mm – 100 mm | Custom sizes available |
| Width / Length | Up to 2500 mm / 12000 mm | Custom fabrication supported |
| Surface Finish | 2B, No.1, BA, HL, No.4 | Multiple options |
| Heat Treatment Condition | Solution Annealed | Standard supply condition |
| Certification | EN 10204 3.1 / 3.2 | Available |
ASTM A240 Type 309S Chemical Composition
The chemical composition of ASTM A240 Type 309S is designed for high-temperature oxidation resistance while keeping carbon at a relatively low level for better weldability.
| Element | Content (%) | Standard Limit | Role |
|---|---|---|---|
| Carbon (C) | ≤ 0.08 | 0.08 max | Low carbon for improved weldability |
| Manganese (Mn) | ≤ 2.00 | 2.00 max | Deoxidation and strength |
| Phosphorus (P) | ≤ 0.045 | 0.045 max | Impurity control |
| Sulfur (S) | ≤ 0.030 | 0.030 max | Cleanliness |
| Silicon (Si) | ≤ 1.00 | 1.00 max | Oxidation resistance at high temperature |
| Chromium (Cr) | 22.00 – 24.00 | 22.00 – 24.00 | High-temperature oxidation resistance |
| Nickel (Ni) | 12.00 – 15.00 | 12.00 – 15.00 | Austenite stability and high-temperature strength |
ASTM A240 Type 309S Mechanical Properties
In the solution-annealed condition, ASTM A240 Type 309S provides good room-temperature strength and excellent high-temperature performance.
| Property | Value | Test Method |
|---|---|---|
| Tensile Strength | ≥ 515 MPa (75 ksi) | ASTM A370 |
| Yield Strength (0.2% Offset) | ≥ 205 MPa (30 ksi) | ASTM A370 |
| Elongation in 50 mm | ≥ 40% | ASTM A370 |
| Hardness | ≤ 217 HB / ≤ 95 HRB | ASTM E10/E18 |
| Density | 8.00 g/cm³ | — |
Delivery Conditions
SHH STEEL supplies ASTM A240 Type 309S primarily in the solution-annealed and pickled condition. Common surface finishes include:
- 2B: Cold-rolled, annealed, pickled and skin-passed
- No.1: Hot-rolled, annealed and pickled (standard for plate)
- BA (Bright Annealed)
- HL (Hairline)
- No.4: Polished finish
Protective PVC film can be applied on request to protect the surface during handling and transportation.
Tolerances
Dimensional tolerances for ASTM A240 Type 309S sheet and plate follow the requirements of ASTM A480/A480M.
Thickness Tolerances Thickness tolerances depend on product form and thickness range. Cold-rolled sheet has tighter tolerances, while hot-rolled plate follows the wider allowable deviations specified in ASTM A480. Tighter-than-standard tolerances can be arranged for precision applications.
Width and Length Tolerances Standard width tolerance is typically +6 mm / 0 mm or better. Length tolerance for cut-to-length plates is normally +10 mm / 0 mm. Closer tolerances and precision cutting (plasma, laser, or waterjet) are available upon request.
Flatness Flatness is controlled according to ASTM A480. For applications requiring superior flatness (such as laser cutting or large fabricated panels), improved flatness material can be supplied.
Edge Condition Sheet is usually supplied with mill edge or slit edge. Plate can be supplied with mill edge, sheared edge, or plasma/laser cut edge according to customer preference.
Weldability
ASTM A240 Type 309S offers good weldability due to its controlled low carbon content.
It can be welded by all common fusion welding processes, including GTAW (TIG), GMAW (MIG), SMAW, and plasma welding. Preheating is generally not required. Matching or slightly over-alloyed filler metals such as ER309L or ER309 are commonly recommended.
Because of the higher chromium and nickel content, the material has good resistance to oxidation in the heat-affected zone. Post-weld cleaning and passivation are recommended to restore optimum corrosion and oxidation resistance, especially for high-temperature service. In most cases, post-weld heat treatment is not necessary.
Equivalent Material Grades
| Grade | Standard | Designation |
|---|---|---|
| Type 309S | ASTM A240 / ASME SA-240 | — |
| UNS S30908 | Unified Numbering System | S30908 |
| 1.4833 | EN 10088 / EN 10095 | X12CrNi23-13 |
| SUS309S | JIS G4304 / G4305 | — |
| 06Cr23Ni13 | GB/T 20878 / GB/T 4237 | Chinese National Standard |
| X12CrNi23-13 | DIN / EN | — |
Applications
ASTM A240 Type 309S is primarily selected for high-temperature service where good oxidation resistance and strength are required. Typical applications are shown below:
| Application Area | Typical Components / Uses |
|---|---|
| Furnace & Heat Treatment | Furnace parts, radiant tubes, muffles, retorts |
| Kiln & Calciner Equipment | Kiln linings, rotary kiln components |
| Power Generation | Boiler tube hangers, heat shields |
| Chemical & Petrochemical | High-temperature process equipment |
| Glass & Ceramics Industry | Glass forming equipment, annealing covers |
| General High-Temperature Service | Thermowells, anchor bolts, structural furnace parts |
Why Choose SHH STEEL
SHH STEEL is a reliable exporter of ASTM A240 Type 309S stainless steel sheet and plate. We provide competitive pricing, flexible custom sizes, multiple surface finishes, and complete Mill Test Certificates.
Our experienced team supports customers with technical advice on material selection and high-temperature applications.
FAQ
- What is the main difference between 309 and 309S?Type 309S has a lower maximum carbon content (0.08% max) compared with standard Type 309 (0.20% max). The lower carbon improves weldability and reduces the risk of intergranular corrosion.
- What is the maximum continuous service temperature for ASTM A240 Type 309S?Approximately 1000–1035°C in continuous service and up to about 1095°C in intermittent service, depending on the environment.
- What is the Chinese equivalent of ASTM A240 Type 309S?The common Chinese designation is 06Cr23Ni13.
- What is the density of ASTM A240 Type 309S?Approximately 8.00 g/cm³.
Conclusion
ASTM A240 Type 309S Stainless Steel Sheet and Plate from SHH STEEL offer excellent high-temperature oxidation resistance, good strength, and improved weldability due to low carbon content. With strict quality control, flexible sizing options, and professional export service, we deliver reliable material for furnace, heat-treatment, and other elevated-temperature applications worldwide.
Contact SHH STEEL today for your ASTM A240 Type 309S requirements.
Keywords of ASTM A240 Type 309S Stainless Steel Sheet & Plate
ASTM A240 309S, ASTM A240 Type 309S, ASTM A240 309S stainless steel plate, ASTM A240 309S sheet, 309S stainless steel plate, 309S stainless steel sheet, SS309S, UNS S30908, 1.4833, SUS309S
Quality Steel Needed? Inquire for Offers
Related Products
