329 Stainless Steel Round Bar
Grade: 329/UNS S32900
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
329 stainless steel is a duplex stainless steel grade designated as UNS S32900. It is a chromium-molybdenum duplex stainless steel that combines the beneficial properties of ferritic and austenitic stainless steels, providing high strength, good toughness, and excellent resistance to corrosion and stress corrosion cracking. The alloy was developed for applications requiring better corrosion resistance and mechanical performance than conventional austenitic stainless steels.
The microstructure of 329 stainless steel consists of a balanced mixture of ferrite and austenite phases. Chromium provides the primary corrosion resistance by forming a stable passive oxide layer, while molybdenum improves resistance to pitting and crevice corrosion, especially in chloride-containing environments. The duplex structure provides higher yield strength than traditional austenitic grades and improves resistance to chloride stress corrosion cracking.
329 stainless steel bars offer good resistance to oxidation, erosion corrosion, and many industrial chemical environments. The material has excellent strength at elevated temperatures and maintains good mechanical stability under demanding service conditions. Compared with 316 stainless steel, 329 provides higher strength and improved resistance to localized corrosion.
329 stainless steel bars are normally supplied in solution annealed condition to achieve the optimum ferrite-austenite balance. Proper heat treatment is important because excessive ferrite or unwanted intermetallic phases can reduce toughness and corrosion resistance. The material has good weldability when appropriate duplex stainless steel welding procedures are applied.
Due to its combination of corrosion resistance, strength, and durability, 329 stainless steel bars are used in chemical processing equipment, heat exchangers, marine components, pressure vessels, pumps, valves, and industrial applications requiring resistance to aggressive environments.
ASTM / JIS / EN Standards
| Standard System | Standard / Grade | Description |
| ASTM | ASTM A276 / A276M – UNS S32900 | Stainless Steel Bars and Shapes |
| ASTM | ASTM A479 / A479M – UNS S32900 | Stainless Steel Bars for Pressure Equipment |
| UNS | S32900 | 329 Duplex Stainless Steel Grade |
| JIS | JIS G4303 SUS329J1 | Duplex Stainless Steel Bars |
| EN | EN 10088-3 1.4460 | X3CrNiMoN27-5-2 Stainless Steel |
| DIN | DIN 1.4460 | 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 1020–1100°C followed by rapid cooling |
| Microstructure | Duplex Ferrite + Austenite Structure |
| Surface Condition | Black Surface, Bright Surface, Ground Surface, Polished Surface |
| Dimensional Tolerance | According to ASTM A276 / ASTM A479 |
| Inspection | Chemical Analysis, Mechanical Testing, Ferrite Content Testing, Dimensional Inspection |
| Supply Condition | Solution Annealed Condition |
Chemical Composition (%)
| Element | Composition Requirement |
| Carbon (C) | ≤ 0.08 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.50 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 23.00 – 28.00 |
| Nickel (Ni) | 3.00 – 6.00 |
| Molybdenum (Mo) | 1.00 – 2.00 |
| Nitrogen (N) | ≤ 0.20 |
| Iron (Fe) | Balance |
Mechanical Properties
Solution Annealed Condition
| Property | Requirement |
| Tensile Strength | ≥ 620 MPa |
| Yield Strength (0.2% Offset) | ≥ 450 MPa |
| Elongation | ≥ 18% |
| Hardness | ≤ 277 HB |
| Condition | Solution Annealed |
| Industry | Applications |
| Chemical Industry | Chemical processing equipment, reactors, tanks |
| Marine Industry | Marine structures, seawater components |
| Power Generation | Heat exchangers, cooling systems |
| Oil & Gas Industry | Pumps, valves, pressure equipment |
| Petrochemical Industry | Processing equipment and piping components |
| Mechanical Engineering | High-strength corrosion-resistant components |
| Industrial Equipment | Shafts, fittings, structural parts |
329 stainless steel is a duplex stainless steel grade designated as UNS S32900. It is a chromium-molybdenum duplex stainless steel that combines the beneficial properties of ferritic and austenitic stainless steels, providing high strength, good toughness, and excellent resistance to corrosion and stress corrosion cracking. The alloy was developed for applications requiring better corrosion resistance and mechanical performance than conventional austenitic stainless steels.
The microstructure of 329 stainless steel consists of a balanced mixture of ferrite and austenite phases. Chromium provides the primary corrosion resistance by forming a stable passive oxide layer, while molybdenum improves resistance to pitting and crevice corrosion, especially in chloride-containing environments. The duplex structure provides higher yield strength than traditional austenitic grades and improves resistance to chloride stress corrosion cracking.
329 stainless steel bars offer good resistance to oxidation, erosion corrosion, and many industrial chemical environments. The material has excellent strength at elevated temperatures and maintains good mechanical stability under demanding service conditions. Compared with 316 stainless steel, 329 provides higher strength and improved resistance to localized corrosion.
329 stainless steel bars are normally supplied in solution annealed condition to achieve the optimum ferrite-austenite balance. Proper heat treatment is important because excessive ferrite or unwanted intermetallic phases can reduce toughness and corrosion resistance. The material has good weldability when appropriate duplex stainless steel welding procedures are applied.
Due to its combination of corrosion resistance, strength, and durability, 329 stainless steel bars are used in chemical processing equipment, heat exchangers, marine components, pressure vessels, pumps, valves, and industrial applications requiring resistance to aggressive environments.
ASTM / JIS / EN Standards
| Standard System | Standard / Grade | Description |
| ASTM | ASTM A276 / A276M – UNS S32900 | Stainless Steel Bars and Shapes |
| ASTM | ASTM A479 / A479M – UNS S32900 | Stainless Steel Bars for Pressure Equipment |
| UNS | S32900 | 329 Duplex Stainless Steel Grade |
| JIS | JIS G4303 SUS329J1 | Duplex Stainless Steel Bars |
| EN | EN 10088-3 1.4460 | X3CrNiMoN27-5-2 Stainless Steel |
| DIN | DIN 1.4460 | 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 1020–1100°C followed by rapid cooling |
| Microstructure | Duplex Ferrite + Austenite Structure |
| Surface Condition | Black Surface, Bright Surface, Ground Surface, Polished Surface |
| Dimensional Tolerance | According to ASTM A276 / ASTM A479 |
| Inspection | Chemical Analysis, Mechanical Testing, Ferrite Content Testing, Dimensional Inspection |
| Supply Condition | Solution Annealed Condition |
Chemical Composition (%)
| Element | Composition Requirement |
| Carbon (C) | ≤ 0.08 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.50 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 23.00 – 28.00 |
| Nickel (Ni) | 3.00 – 6.00 |
| Molybdenum (Mo) | 1.00 – 2.00 |
| Nitrogen (N) | ≤ 0.20 |
| Iron (Fe) | Balance |
Mechanical Properties
Solution Annealed Condition
| Property | Requirement |
| Tensile Strength | ≥ 620 MPa |
| Yield Strength (0.2% Offset) | ≥ 450 MPa |
| Elongation | ≥ 18% |
| Hardness | ≤ 277 HB |
| Condition | Solution Annealed |
| Industry | Applications |
| Chemical Industry | Chemical processing equipment, reactors, tanks |
| Marine Industry | Marine structures, seawater components |
| Power Generation | Heat exchangers, cooling systems |
| Oil & Gas Industry | Pumps, valves, pressure equipment |
| Petrochemical Industry | Processing equipment and piping components |
| Mechanical Engineering | High-strength corrosion-resistant components |
| Industrial Equipment | Shafts, fittings, structural parts |
