309 / 309S / 309H Stainless Steel Bar

309, 309S, and 309H austenitic stainless steel bars are high-temperature alloys designed for excellent oxidation and heat resistance up to 1100°C. With a balanced composition of chromium and nickel, these grades provide superior strength, corrosion resistance, and thermal stability. 309S offers lower carbon content for better weldability, while 309H contains higher carbon for enhanced high-temperature strength. Commonly used in furnaces, boilers, heat exchangers, and chemical processing equipment, SakySteel supplies these bars in hot-rolled, cold-drawn, and polished conditions, ensuring reliable performance under extreme environments.

For optimum performance, 309, 309S, and 309H stainless steels should undergo the following recommended heat treatment procedures:

• Solution Annealing: Heat the material to 1832–2101°F (1000–1150°C), then quench rapidly to dissolve carbides and achieve maximum corrosion resistance.

• Sigma Phase Restoration: Prolonged service between 1202–1742°F (650–950°C) may cause embrittlement due to sigma phase formation. Performing a solution anneal at 2012–2102°F (1100–1150°C) helps restore ductility and toughness.

• Hot Forming: For hot working, heat evenly to 1742–2192°F (950–1200°C). After forming, a final annealing treatment at 1832–2101°F (1000–1150°C) followed by rapid cooling is recommended to maintain structure stability.

These grades cannot be hardened by heat treatment. The higher carbon levels in standard 309 and 309H enhance creep strength but can increase susceptibility to carbide precipitation during welding or extended exposure at intermediate temperatures. For applications requiring extensive welding, 309S, with its lower carbon content, is the preferred option.

To ensure the highest quality and performance, all SAKY STEEL bar products can be tested through a comprehensive range of in-site inspections. These tests verify chemical composition, mechanical integrity, and microstructural stability directly on materials before shipment or after processing.

At SAKY STEEL, we ensure every batch of material meets the  international standards through comprehensive chemical composition analysis. Our advanced laboratory is equipped with state-of-the-art instruments, including Optical Emission Spectrometer (OES), Positive Material Identification (PMI) device, Inductively Coupled Plasma Spectrometer (ICP), and X-Ray Fluorescence (XRF) analyzer.

At SAKY STEEL, we conduct a full range of mechanical performance tests to ensure the strength, toughness, and durability of every stainless steel, alloy steel, and nickel alloy product we deliver.We perform comprehensive tests such as tensile strength, yield strength, elongation, hardness (Brinell, Rockwell, Vickers, Leeb), bending, impact toughness, fatigue, and fracture toughness (KIC and CTOD). These tests precisely measure the mechanical behavior of materials under various loads and environments, ensuring full compliance with ASTM, EN, GB, and ISO standards. 

309, 309S, and 309H stainless steel bars are widely used in high-temperature and corrosive service environments where strength, oxidation resistance, and structural stability are critical. These grades perform exceptionally well in both continuous and intermittent heating conditions, making them ideal for thermal process equipment and heavy industrial use.

Typical applications include:

• Furnace parts, burner nozzles, and heat treatment baskets

• Boiler tubes, superheater supports, and heat exchanger components

• Chemical processing and petrochemical equipment

• Kiln liners, retorts, and radiant tubes

• Exhaust systems and flue gas components in power generation

• Expansion joints, combustion chambers, and refractory anchors

• Food processing and thermal oxidation systems

With their excellent combination of strength, corrosion resistance, and heat stability, SakySteel 309 / 309S / 309H stainless steel bars ensure long service life and reliable performance in demanding industrial environments.

Q1: What is the main difference between 309, 309S, and 309H?
309S has lower carbon for better weldability, while 309H has higher carbon for improved high-temperature strength.

Q2: Can these grades be hardened by heat treatment?
No. 309, 309S, and 309H are austenitic steels; they can only be strengthened by cold working.

Q3: What is the service temperature range?
They resist oxidation and scaling up to about 1100°C (2010°F).

Q4: What are common applications?
Furnaces, boilers, heat exchangers, exhaust systems, and chemical processing equipment.

Q5: Which surface finishes are available?
Hot-rolled, cold-drawn, polished, and bright bars supplied by SakySteel.

Reliable Quality – Our stainless steel bars, pipes, coils, and flanges are manufactured to meet international standards such as ASTM, AISI, EN, and JIS.

Strict Inspection – Every product undergoes ultrasonic testing, chemical analysis, and dimensional control to ensure high performance and traceability.

Strong Stock & Fast Delivery – We maintain regular inventory of key products to support urgent orders and global shipping.

Customized Solutions – From heat treatment to surface finish, SAKYSTEEL offers tailor-made options to match your exact requirements.

Professional Team – With years of export experience, our sales and technical support team ensures smooth communication, quick quotations, and full documentation service.

1. Visual Dimension Test
2. Mechanical examining like tensile, Elongation and reduction of area.
3. Impact analysis
4. Chemical examination analysis
5. Hardness test
6. Pitting protection test
7. Penetrant Test
8. Intergranular Corrosion Testing
9. Roughness Testing
10. Metallography Experimental Testg

1. Packing is quite important especially in a case of international shipments in which consignment pass through various channels to reach the ultimate destination, so we put special concern regarding packaging.
2. Saky Steel’s pack our goods in numerous ways based on the products. We pack our products in multiple ways, such as,