303 Stainless Steel Round Bar
Grade: 303/UNS S30300
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
303 stainless steel is a free-machining austenitic stainless steel developed from 304 stainless steel by adding sulfur to improve machinability. The sulfur addition enhances cutting performance, chip breaking, and production efficiency, making 303 widely used for automatic machining applications. It maintains good toughness, dimensional stability, and general corrosion resistance. Compared with 304, its corrosion resistance and weldability are slightly reduced due to sulfur content. It is mainly selected for precision-machined components where manufacturing efficiency and close tolerances are important.
| Standard | Designation |
| ASTM / UNS | Type 303 / UNS S30300 |
| JIS | SUS303 |
| EN | 1.4305 / X8CrNiS18-9 |
| Standard | Description |
| ASTM A276/A276M | Stainless Steel Bars and Shapes |
| ASTM A479/A479M | Stainless Steel Bars 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) | ≤0.15 |
| Chromium (Cr) | 17.00-19.00 |
| Nickel (Ni) | 8.00-10.00 |
| Manganese (Mn) | ≤2.00 |
| Silicon (Si) | ≤1.00 |
| Sulfur (S) | 0.15 minimum |
| Iron (Fe) | Balance |
Mechanical Properties (Annealed Condition)
| Property | Value |
| Tensile Strength | ≥515 MPa |
| Yield Strength | ≥205 MPa |
| Elongation | ≥40% |
| Hardness | ≤201 HB |
| Density | Approx. 8.0 g/cm³ |
Automatic screw machine components
• Shafts and bushings
• Valves and fittings
• Fasteners
• Precision mechanical parts
• Electrical components


303 stainless steel is a free-machining austenitic stainless steel developed from 304 stainless steel by adding sulfur to improve machinability. The sulfur addition enhances cutting performance, chip breaking, and production efficiency, making 303 widely used for automatic machining applications. It maintains good toughness, dimensional stability, and general corrosion resistance. Compared with 304, its corrosion resistance and weldability are slightly reduced due to sulfur content. It is mainly selected for precision-machined components where manufacturing efficiency and close tolerances are important.
| Standard | Designation |
| ASTM / UNS | Type 303 / UNS S30300 |
| JIS | SUS303 |
| EN | 1.4305 / X8CrNiS18-9 |
| Standard | Description |
| ASTM A276/A276M | Stainless Steel Bars and Shapes |
| ASTM A479/A479M | Stainless Steel Bars 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) | ≤0.15 |
| Chromium (Cr) | 17.00-19.00 |
| Nickel (Ni) | 8.00-10.00 |
| Manganese (Mn) | ≤2.00 |
| Silicon (Si) | ≤1.00 |
| Sulfur (S) | 0.15 minimum |
| Iron (Fe) | Balance |
Mechanical Properties (Annealed Condition)
| Property | Value |
| Tensile Strength | ≥515 MPa |
| Yield Strength | ≥205 MPa |
| Elongation | ≥40% |
| Hardness | ≤201 HB |
| Density | Approx. 8.0 g/cm³ |
Automatic screw machine components
• Shafts and bushings
• Valves and fittings
• Fasteners
• Precision mechanical parts
• Electrical components






