309S Stainless Steel Round Bar
Grade: 309S/UNS S30908
Size:
Cold drawn: φ4mm-φ60mm
Hot Rolled: φ16mm-φ230mm
Forged: φ230mm-φ1200mm
Surface Finish: Black Annealed, Polished Bright, Centerless Grinding
Diameter Tolerance: H9, H11, h9, h11 etc
- Fast Shipping / Ready Stock
- ISO 9001 Direct Factory
- Custom Cutting & Processing
- 100% MTC & SGS Inspection Supported
309S stainless steel is a high-alloy austenitic stainless steel designed primarily for elevated-temperature service. ”
“It contains higher chromium and nickel contents than conventional 304 stainless steel, providing improved oxidation resistance, ”
“high-temperature strength, and resistance to carburizing and sulfidizing environments.
The increased chromium content forms a stable protective oxide layer during high-temperature exposure, while nickel enhances ”
“austenitic stability and improves resistance to thermal cycling. 309S maintains good toughness and corrosion resistance in both ”
“high-temperature and moderately corrosive environments.
Compared with standard austenitic stainless steels, 309S provides superior performance in furnace components, heat treatment equipment, ”
“combustion systems, and petrochemical processing applications where materials are exposed to elevated temperatures. The low carbon ”
“content improves weldability and reduces the risk of carbide precipitation during welding.
309S has good fabrication characteristics, including welding, forming, and machining capability. It is commonly supplied as bars, ”
“plates, sheets, pipes, and fabricated components according to ASTM, JIS, and EN standards. Stainless steel bars manufactured from ”
“309S are widely used for high-temperature structural parts, supports, shafts, and industrial furnace components.
Standard Designations
| Standard | Designation |
| ASTM / UNS | Type 309S / UNS S30908 |
| JIS | SUS309S |
| EN | 1.4833 / X12CrNi23-13 |
Bar Production Standards
| Standard | Description |
| ASTM A276/A276M | Stainless Steel Bars and Shapes |
| ASTM A479/A479M | Stainless Steel Bars and Shapes for Pressure Vessel Service |
| ASTM A484/A484M | General Requirements for Stainless Steel Bars |
| JIS G4303 | Stainless Steel Bars |
| EN 10088-3 | Stainless Steel Bars and Rods |
Chemical Composition (Typical wt.%)
| Element | Value |
| Carbon (C) | ≤0.08 |
| Chromium (Cr) | 22.00-24.00 |
| Nickel (Ni) | 12.00-15.00 |
| Manganese (Mn) | ≤2.00 |
| Silicon (Si) | ≤1.00 |
| Phosphorus (P) | ≤0.045 |
| Sulfur (S) | ≤0.030 |
| Iron (Fe) | Balance |
Mechanical Properties (Annealed Condition)
| Property | Value |
| Tensile Strength | ≥515 MPa |
| Yield Strength (0.2% Offset) | ≥205 MPa |
| Elongation | ≥40% |
| Hardness (Brinell) | ≤217 HB |
| Hardness (Rockwell B) | ≤95 HRB |
| Density | Approx. 7.98 g/cm³ |
| Modulus of Elasticity | Approx. 200 GPa |
- Furnace components
- Heat treatment equipment
- Combustion chambers
- Petrochemical processing equipment
- High-temperature piping systems
- Heat exchangers
- Kiln and oven parts
- Industrial thermal processing equipment


309S stainless steel is a high-alloy austenitic stainless steel designed primarily for elevated-temperature service. ”
“It contains higher chromium and nickel contents than conventional 304 stainless steel, providing improved oxidation resistance, ”
“high-temperature strength, and resistance to carburizing and sulfidizing environments.
The increased chromium content forms a stable protective oxide layer during high-temperature exposure, while nickel enhances ”
“austenitic stability and improves resistance to thermal cycling. 309S maintains good toughness and corrosion resistance in both ”
“high-temperature and moderately corrosive environments.
Compared with standard austenitic stainless steels, 309S provides superior performance in furnace components, heat treatment equipment, ”
“combustion systems, and petrochemical processing applications where materials are exposed to elevated temperatures. The low carbon ”
“content improves weldability and reduces the risk of carbide precipitation during welding.
309S has good fabrication characteristics, including welding, forming, and machining capability. It is commonly supplied as bars, ”
“plates, sheets, pipes, and fabricated components according to ASTM, JIS, and EN standards. Stainless steel bars manufactured from ”
“309S are widely used for high-temperature structural parts, supports, shafts, and industrial furnace components.
Standard Designations
| Standard | Designation |
| ASTM / UNS | Type 309S / UNS S30908 |
| JIS | SUS309S |
| EN | 1.4833 / X12CrNi23-13 |
Bar Production Standards
| Standard | Description |
| ASTM A276/A276M | Stainless Steel Bars and Shapes |
| ASTM A479/A479M | Stainless Steel Bars and Shapes for Pressure Vessel Service |
| ASTM A484/A484M | General Requirements for Stainless Steel Bars |
| JIS G4303 | Stainless Steel Bars |
| EN 10088-3 | Stainless Steel Bars and Rods |
Chemical Composition (Typical wt.%)
| Element | Value |
| Carbon (C) | ≤0.08 |
| Chromium (Cr) | 22.00-24.00 |
| Nickel (Ni) | 12.00-15.00 |
| Manganese (Mn) | ≤2.00 |
| Silicon (Si) | ≤1.00 |
| Phosphorus (P) | ≤0.045 |
| Sulfur (S) | ≤0.030 |
| Iron (Fe) | Balance |
Mechanical Properties (Annealed Condition)
| Property | Value |
| Tensile Strength | ≥515 MPa |
| Yield Strength (0.2% Offset) | ≥205 MPa |
| Elongation | ≥40% |
| Hardness (Brinell) | ≤217 HB |
| Hardness (Rockwell B) | ≤95 HRB |
| Density | Approx. 7.98 g/cm³ |
| Modulus of Elasticity | Approx. 200 GPa |
- Furnace components
- Heat treatment equipment
- Combustion chambers
- Petrochemical processing equipment
- High-temperature piping systems
- Heat exchangers
- Kiln and oven parts
- Industrial thermal processing equipment






