304 Stainless Steel Round Bar | Versatile Corrosion Resistance for Precision Machining
✓ All-Purpose Durability: Survives 500+ hours in ASTM B117 salt spray testing – ideal for marine-adjacent applications.
✓ Precision Machinability: Free-machining grades available (304MQ) with 20% improved chip-breaking efficiency.
✓ Hygienic Compliance: Passes FDA CFR 175.300 for food processing equipment and pharmaceutical tooling.
✓ Batch Consistency: Controlled annealing (1050°C ±15°C) ensures uniform hardness (HB 170-200).
304 Stainless Steel Round Bar (UNS S30400)
A cornerstone of industrial manufacturing, 304 stainless steel round bars deliver exceptional corrosion resistance, weldability, and machinability for high-performance components. With 18% chromium and 8% nickel alloy composition, these bars excel in mildly corrosive environments while maintaining structural integrity across temperatures from -196°C to 800°C (-321°F to 1472°F). Certified to ASTM A276/A479 and EN 10088-2, they are the go-to choice for shafts, fasteners, valves, and architectural frameworks.
Diameter Range: 6mm–300mm (hot-rolled ±0.5%; cold-finished ±0.1mm tolerance)
Length: 3m–6m standard (cut-to-length precision ±2mm)
Surface Finishes: Black, Peeled, Polished (Ra ≤0.8μm), or Ground (Ra ≤0.4μm)
Mechanical Properties: Yield Strength ≥205 MPa | Tensile Strength ≥515 MPa | Elongation ≥40%
| Parameter Category | Value/Description |
|---|---|
| Material Grade | UNS S30400 (per ASTM A276) |
| Composition (%) | C≤0.08, Cr 18.0-20.0, Ni 8.0-10.5, Mn≤2.0, Si≤1.0, P≤0.045, S≤0.03 |
| Tensile Strength (MPa) | ≥515 (Annealed) |
| Yield Strength (MPa) | ≥205 (Annealed) |
| Elongation (%) | ≥40 (50mm gauge length) |
| Hardness | Brinell (HB): ≤201; Rockwell (HRB): ≤92 (Annealed) |
| Density (g/cm³) | 8.03 |
| Melting Range | 1400-1450℃ |
| Thermal Conductivity (W/m·K) | 16.2 (20℃) |
| Thermal Expansion (10⁻⁶/℃) | 17.2 (20-100℃) |
| Electrical Resistivity (Ω·m) | 0.72×10⁻⁶ (20℃) |
| Elastic Modulus (GPa) | 193 |
| Magnetic Properties | Non-magnetic (Annealed) |
| Corrosion Resistance | Excellent resistance to general corrosion, oxidizing acids, and organic acids; moderate intergranular corrosion resistance (avoid sensitization) |
| Heat Treatment | Annealing: 1010-1120℃ followed by rapid cooling (water or air quenching) |
| Surface Finishes | Black (Hot-rolled), Turned, Polished, Pickling & Passivation |
| Dimension Range | Diameter: 5mm-300mm; Length: 3000mm/6000mm (standard) |
| Standards | ASTM A276/A479, EN 10088-3, JIS G4303, GB/T 1220 |
| Applications | Shafts, fasteners, pump/valve components, food processing equipment, medical devices, structural components |
304 Stainless Steel Round Bar Applications
| Industry | Critical Components | 304 Round Bar Advantage |
|---|---|---|
| Food & Beverage | Mixer shafts, valve stems | Withstands CIP cleaning with 3% caustic soda solutions. |
| Chemical Plants | Pump shafts, reactor agitators | Resists 10% nitric acid at 50°C (122°F). |
| Automotive | Suspension bolts, turbocharger shafts | Fatigue strength 30% higher than carbon steel equivalents. |
| Architecture | Balustrades, seismic reinforcement rods | 0.5mm/m straightness tolerance for precision installations. |
304 Stainless Steel Round Bar Product Packaging
304 Stainless Steel Round Bar are precision-engineered for superior corrosion resistance and mechanical strength, meeting ASTM A276 and ISO 3506 standards. To ensure optimal performance from factory to your facility, we implement rigorous packaging protocols and logistics safeguards.
Small Bars (<50mm)
Bundled with steel straps + VCI-coated wraps, crated on reinforced wooden pallets.
Large Bars (≥50mm)
End caps + edge protectors, stacked in custom steel racks with desiccant units.
Anti-Scratch Sleeving
Silicone-impregnated fabric for polished/ground surfaces.
RFID Tags
Embedded tracking chips with real-time material certification access.
Why Choose Us
Where Precision Meets Partnership，25 years of focus on metal material science，Not only a supplier, but also your engineering consultant，Fast and zero compromise，Sustainable trust cycle。
Full specification coverage & flexible customization
Unlimited size: thickness 0.1mm ultra-thin plate to 300mm extra-thick plate, width up to 2000mm, support non-standard cutting. Various surface treatments: 2B, BA mirror, brushed (No.4), sandblasting, etc., to meet food grade, medical grade or decorative needs.
Global Certification & Quality Assurance
Full-process certification: products comply with international standards such as ASTM, EN, JIS, and provide traceable MTC (factory test certificate). Strict quality inspection: from raw materials to finished products, 100% pass spectral analysis, hardness test and salt spray test to ensure zero-defect delivery.
Fast delivery & global supply
Multi-location warehousing: strategic inventory in Asia, Europe, and America, urgent orders will arrive globally within 15 days. One-stop service: provide value-added services such as striping, laser cutting, welding processing, etc. to shorten customer production cycle.
Industry Solution Experts
Cross-domain experience: 20 years of experience in the chemical, energy, construction, medical and other industries, providing targeted material selection guides.
Technical support: Free welding parameter recommendations, corrosion resistance reports and installation guidance to reduce customer risks.
Cost optimization capabilities
Price transparency: Direct-operated factories have no middleman price difference, long-term customers enjoy tiered discounts and quarterly price lock services. Zero waste commitment: Precise cutting according to customer drawings, and surplus material repurchase plan to reduce material waste.
Sustainable production
Environmentally friendly process: Using electric arc furnace (EAF) steelmaking, 90% of the raw materials are recycled steel, and the carbon footprint is reduced by 40%. Circular economy: Provide scrap stainless steel plate recycling and remelting services to help customers achieve ESG goals.
304 Stainless Steel Round Bar Shipping
Sea transport
40HQ container (loading capacity 28 tons) / bulk carrier (LCL minimum 1 ton)
Air transport
reach major airports around the world within 7 days (DDP/DAP terms)
Land transport
door-to-door within China (qualification for dangerous goods transportation)
Our Services
We guarantee global door-to-door delivery within 7–15 business days via partnerships with DHL, Maersk, and UPS.
FAQ
Q1: How does 304 differ from 303 stainless steel bars?
A: 304 offers superior corrosion resistance; 303 contains sulfur for enhanced machinability but is unsuitable for welding or marine environments.
Q2: What surface finish minimizes galling in threaded applications?
A: Specify Electroless Nickel-PTFE Coating – reduces friction coefficient by 65% vs polished finishes.
Q3: What’s the minimum order quantity?
Standard sizes: 1000kg.
Custom diameters/lengths: 5 ton (21-day lead time).
Q4: How to prevent intergranular corrosion during welding?
A:Use 304L grade for bars >6mm diameter or post-weld annealing at 1050°C (1922°F).
Q5: What certifications ensure material quality?
Every shipment includes:
- EN 10204 3.1 Mill Certificate
- RoHS/REACH Compliance Statement
- Ultrasonic Testing Report (ASTM A388)
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