904L Stainless Steel Round Bar
Grade: 904L/UNS N08904
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
904L stainless steel is a high-alloy austenitic super stainless steel grade designated as UNS N08904. It was developed specifically for applications requiring exceptional corrosion resistance, especially in highly acidic environments containing sulfuric acid, phosphoric acid, chlorides, and other aggressive chemicals. The alloy contains high levels of nickel, chromium, molybdenum, and copper, providing superior corrosion resistance compared with conventional stainless steels such as 316L.
The high chromium content of 904L stainless steel provides excellent resistance to general corrosion by forming a stable passive chromium oxide layer. The high nickel content improves resistance to stress corrosion cracking and provides excellent stability in reducing environments. Molybdenum significantly enhances resistance to pitting and crevice corrosion, while copper improves resistance to sulfuric acid and other reducing acids.
904L stainless steel bars are fully austenitic and maintain excellent toughness and ductility even at cryogenic temperatures. The low carbon content minimizes carbide precipitation during welding, reducing the risk of intergranular corrosion. The material offers excellent weldability and maintains corrosion resistance in welded conditions without requiring post-weld heat treatment.
Due to its exceptional corrosion resistance, 904L stainless steel bars are widely used in chemical processing equipment, sulfuric acid plants, pharmaceutical equipment, seawater systems, pollution control equipment, heat exchangers, storage tanks, and high-performance industrial applications. It is especially suitable where standard stainless steels such as 316L cannot provide sufficient corrosion resistance.
ASTM / JIS / EN Standards
| Standard System | Standard / Grade | Description |
| ASTM | ASTM A276 / A276M – UNS N08904 | Stainless Steel Bars and Shapes |
| ASTM | ASTM A479 / A479M – UNS N08904 | Stainless Steel Bars for Pressure Equipment |
| ASTM | ASTM B649 – UNS N08904 | Nickel-Iron-Chromium-Molybdenum Alloy Bar |
| UNS | N08904 | 904L Stainless Steel Grade |
| JIS | JIS G4303 SUS890L | Stainless Steel Bars |
| EN | EN 10088-3 1.4539 | X1NiCrMoCu25-20-5 Stainless Steel |
| DIN | DIN 1.4539 | Equivalent European Material Designation |
Stainless Steel Bar Execution Standards
| Item | Specification |
| Product Type | Round Bar, Square Bar, Hexagonal Bar |
| Manufacturing Process | Hot Rolled, Cold Drawn, Peeled, Ground, Polished |
| Heat Treatment | Solution Annealing |
| Solution Treatment Temperature | Approximately 1090–1175°C followed by rapid cooling |
| Microstructure | Fully Austenitic |
| Surface Condition | Black Surface, Bright Surface, Ground Surface, Polished Surface |
| Dimensional Tolerance | According to ASTM A276 / ASTM A479 |
| Inspection | Chemical Analysis, Mechanical Testing, Intergranular Corrosion Testing, Dimensional Inspection |
| Supply Condition | Solution Annealed Condition |
Chemical Composition (%)
| Element | Composition Requirement |
| Carbon (C) | ≤ 0.020 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.035 |
| Chromium (Cr) | 19.00 – 23.00 |
| Nickel (Ni) | 23.00 – 28.00 |
| Molybdenum (Mo) | 4.00 – 5.00 |
| Copper (Cu) | 1.00 – 2.00 |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
Mechanical Properties
Solution Annealed Condition
| Property | Requirement |
| Tensile Strength | ≥ 490 MPa |
| Yield Strength (0.2% Offset) | ≥ 220 MPa |
| Elongation | ≥ 35% |
| Hardness | ≤ 70 HRB / ≤ 220 HB |
| Condition | Solution Annealed |
| Industry | Applications |
| Chemical Industry | Sulfuric acid equipment, reactors, storage tanks |
| Pharmaceutical Industry | High-purity processing equipment |
| Oil & Gas Industry | Acid processing equipment, corrosion-resistant components |
| Marine Industry | Seawater piping, heat exchangers, offshore equipment |
| Pollution Control | Scrubbers, flue gas treatment systems |
| Power Generation | Condensers, cooling water systems |
| Food Industry | High-corrosion sanitary equipment |
904L stainless steel is a high-alloy austenitic super stainless steel grade designated as UNS N08904. It was developed specifically for applications requiring exceptional corrosion resistance, especially in highly acidic environments containing sulfuric acid, phosphoric acid, chlorides, and other aggressive chemicals. The alloy contains high levels of nickel, chromium, molybdenum, and copper, providing superior corrosion resistance compared with conventional stainless steels such as 316L.
The high chromium content of 904L stainless steel provides excellent resistance to general corrosion by forming a stable passive chromium oxide layer. The high nickel content improves resistance to stress corrosion cracking and provides excellent stability in reducing environments. Molybdenum significantly enhances resistance to pitting and crevice corrosion, while copper improves resistance to sulfuric acid and other reducing acids.
904L stainless steel bars are fully austenitic and maintain excellent toughness and ductility even at cryogenic temperatures. The low carbon content minimizes carbide precipitation during welding, reducing the risk of intergranular corrosion. The material offers excellent weldability and maintains corrosion resistance in welded conditions without requiring post-weld heat treatment.
Due to its exceptional corrosion resistance, 904L stainless steel bars are widely used in chemical processing equipment, sulfuric acid plants, pharmaceutical equipment, seawater systems, pollution control equipment, heat exchangers, storage tanks, and high-performance industrial applications. It is especially suitable where standard stainless steels such as 316L cannot provide sufficient corrosion resistance.
ASTM / JIS / EN Standards
| Standard System | Standard / Grade | Description |
| ASTM | ASTM A276 / A276M – UNS N08904 | Stainless Steel Bars and Shapes |
| ASTM | ASTM A479 / A479M – UNS N08904 | Stainless Steel Bars for Pressure Equipment |
| ASTM | ASTM B649 – UNS N08904 | Nickel-Iron-Chromium-Molybdenum Alloy Bar |
| UNS | N08904 | 904L Stainless Steel Grade |
| JIS | JIS G4303 SUS890L | Stainless Steel Bars |
| EN | EN 10088-3 1.4539 | X1NiCrMoCu25-20-5 Stainless Steel |
| DIN | DIN 1.4539 | Equivalent European Material Designation |
Stainless Steel Bar Execution Standards
| Item | Specification |
| Product Type | Round Bar, Square Bar, Hexagonal Bar |
| Manufacturing Process | Hot Rolled, Cold Drawn, Peeled, Ground, Polished |
| Heat Treatment | Solution Annealing |
| Solution Treatment Temperature | Approximately 1090–1175°C followed by rapid cooling |
| Microstructure | Fully Austenitic |
| Surface Condition | Black Surface, Bright Surface, Ground Surface, Polished Surface |
| Dimensional Tolerance | According to ASTM A276 / ASTM A479 |
| Inspection | Chemical Analysis, Mechanical Testing, Intergranular Corrosion Testing, Dimensional Inspection |
| Supply Condition | Solution Annealed Condition |
Chemical Composition (%)
| Element | Composition Requirement |
| Carbon (C) | ≤ 0.020 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.035 |
| Chromium (Cr) | 19.00 – 23.00 |
| Nickel (Ni) | 23.00 – 28.00 |
| Molybdenum (Mo) | 4.00 – 5.00 |
| Copper (Cu) | 1.00 – 2.00 |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
Mechanical Properties
Solution Annealed Condition
| Property | Requirement |
| Tensile Strength | ≥ 490 MPa |
| Yield Strength (0.2% Offset) | ≥ 220 MPa |
| Elongation | ≥ 35% |
| Hardness | ≤ 70 HRB / ≤ 220 HB |
| Condition | Solution Annealed |
| Industry | Applications |
| Chemical Industry | Sulfuric acid equipment, reactors, storage tanks |
| Pharmaceutical Industry | High-purity processing equipment |
| Oil & Gas Industry | Acid processing equipment, corrosion-resistant components |
| Marine Industry | Seawater piping, heat exchangers, offshore equipment |
| Pollution Control | Scrubbers, flue gas treatment systems |
| Power Generation | Condensers, cooling water systems |
| Food Industry | High-corrosion sanitary equipment |
