1. Standard Designations

• 309 UNS: S30900

• 309S UNS: S30908

• ASTM: A312/A312M (Seamless & Welded)

• ASTM: A358/A358M (EFW)

• EN: 1.4828

• JIS: SUS 309/SUS 309S

2. Chemical Composition (% by weight)

3. Mechanical Properties (Room Temperature)

4. High-Temperature Properties

• Maximum Service Temperature: 1150°C (Continuous), 1035°C (Intermittent)

• Oxidation Resistance: Excellent due to high chromium content

• Creep Strength: Good mechanical strength retention

• Thermal Stability: Resists scaling under cyclic conditions

5. Physical Properties

6. Product Range & Specifications

7. Manufacturing Processes

• Seamless Pipe: Hot extruded, Cold drawn

• Welded Pipe: EFW, TIG Welded

8. Surface Finishes

• Annealed & Pickled: Standard finish

• Mechanically Polished: For specific applications

• Bead Blasted: Uniform matte surface

9. Typical Applications

• Furnace radiant tubes and components

• Heat treatment equipment

• Kiln furniture and internal structures

• Thermal processing conveyor systems

• Refinery and chemical furnace tubes

• Heat exchanger tubes in high-temperature service

Quality Assurance:

• Hydrostatic testing per ASTM standards

• Ultrasonic testing for seamless pipes

• Radiographic testing for welded pipes

• PMI (Positive Material Identification)

• Full material traceability

Technical Notes:

• Excellent oxidation resistance up to 1150°C

• 309S preferred for welded applications

• Good resistance to sulfur-containing atmospheres

• Suitable for both oxidizing and reducing environments

• Maintains strength better than 304/316 grades at high temperatures

All pipes supplied with full certification and meet international quality standards for high-temperature service applications.