The battle against corrosion in offshore rigs, pharmaceutical reactors, and power plant heat exchangers reached a turning point when one plant manager specified 904L Round Bars. Designed to conquer sulfuric acid attack, chloride stress, and extreme operating conditions, these bars redefine reliability for procurement heads, engineers, and OEMs in marine, chemical, oil & gas, pharma, and power sectors. Aurico Alloys LLP 904L Round Bars form the backbone of projects demanding the best in certified purity and structural security.
Table of Contents:
Grade 904L (UNS N08904, WNR 1.4539) is a non-stabilized, low-carbon high-nickel stainless that leverages 23–28% Ni, 19–23% Cr, 4–5% Mo, and 1–2% Cu for unbeatable resistance to reducing acids, chloride-induced pitting/crevice corrosion, and stress corrosion cracking even where 316L and 317L fail. With excellent weldability, machinability, and fatigue strength, it's a mainstay for seawater applications, high-pressure chemical service, and critical marine/energy hardware.
Aurico Alloys LLP stocks and custom-cuts 904L round bars to ASTM A479, A276, EN 10272, DIN 1.4539, delivered from 3mm up to 800mm in bright, ground, and rough-turned finishes. Every piece is supplied with mill test certificates, RoHS, REACH credentials, and full documentation for international compliance serving urgent repair and steady supply needs for hardware stores and energy projects.
904L round bars preserve mechanical strength (yield ≥220 MPa, tensile ≥490 MPa, elongation ≥35%) and hardness under harsh operating conditions (up to 850–1150°C). Their outstanding formability makes them vital for quick project turnarounds, precise fabrication for pumps, pressure vessels, reactors, and heat exchangers supporting decades of safe operation.
High-quality 904L Round Bar ready for industrial use.
Specification Overview
| Supplier & Manufacturer | Aurico Alloys LLP |
|---|---|
| Grade | 904L (UNS N08904, WNR 1.4539) |
| Standards | ASTM A479, A276, EN 10272, DIN 1.4539 |
| Diameter Range | 3mm – 800mm |
| Length | up to 6m, cut lengths available |
| Finish | Bright, ground, rough turned, black, polished |
| Delivery | Direct stock, custom machining, all certifications, urgent shipment |
Equivalent Grades & Standards
| Property | Value |
|---|---|
| UNS number | N08904 |
| Werkstoff / EN number | 1.4539 |
| EN designation | X1NiCrMoCu25-20-5 |
| Density | 8.00 g/cm3 |
| Melting range | 1383 °C |
| Specific heat (20°C) | 460 J/kg·K |
| Thermal conductivity (20°C) | 11.9 W/m·K |
| Coefficient of expansion (20–200°C) | 18.4 µm/m·K |
| Coefficient of expansion (20–400°C) | 18.0 µm/m·K |
| Coefficient of expansion (20–600°C) | 18.0 µm/m·K |
| Coefficient of expansion (20–800°C) | 18.2 µm/m·K |
| Coefficient of expansion (20–1000°C) | 18.5 µm/m·K |
| Electrical resistivity (20°C) | 0.935 Ω·mm²/m |
| Magnetic permeability (at 0.8 kA/m DC or AC at 20°C) | < 1.05 |
| Young's modulus (20°C) | 200 GPa |
| Oil and gas conformance | NACE MR0175 / ISO 15156-3 · NACE MR0103 / ISO 17945 (Aperam 904L Technical Data Sheet) |
| Rod and bar specification | ASTM A479 / EN 10088-3 |
Identifiers and physical constants for 904L. A dash means no such designation is published for this grade.
Stock & Product Availability
Aurico Alloys LLP delivers 904L round bars in full size range from rapid stock, with PMT, batch reports, RoHS/REACH and full traceability for energy/chemical/marine projects.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Carbon (C) | — | 0.020 |
| Manganese (Mn) | — | 2.00 |
| Phosphorus (P) | — | 0.045 |
| Sulfur (S) | — | 0.035 |
| Silicon (Si) | — | 1.00 |
| Chromium (Cr) | 19.0 | 23.0 |
| Nickel (Ni) | 23.0 | 28.0 |
| Molybdenum (Mo) | 4.00 | 5.00 |
| Copper (Cu) | 1.00 | 2.00 |
| Nitrogen (N) | — | 0.10 |
Composition limits for 904L. These are specification limits for the grade, not measured values for a lot; the mill test certificate supplied with your order states the actual analysis.
Mechanical & Physical Properties
| Property | Standard Value |
|---|---|
| Tensile Strength (MPa) | 490 (min) |
| Yield Strength, 0.2% MPa | 220 (min) |
| Elongation (%) | 35 (min) |
| Hardness (HB) | 217–269 |
| Max Service Temp (°C) | 850–1150 |
Applications & Benefits
- Chemical plants: reactors, tanks, heat exchangers, piping for sulfuric/acetic/chloride service
- Marine: seawater, brine pumps, offshore rigs, shipboard hardware
- Oil & gas: downhole tools, pressure valves, aggressive process lines
- Power: turbine blades, superheaters, heat exchangers, nuclear plant hardware
- Pharma: process vessels, reactor units, clean-in-place modules
- Hardware/OEM/fabricators: bars for machine shops, urgent field repair stock
FAQ & Search Trends
Global Export Destinations
We ship worldwide from Mumbai. See every destination we export to on our export markets page.
Domestic Supply Network
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
Aurico Alloys LLP 904L Round Bars safeguard critical chemical, marine, pharma, energy, and oil & gas assets against corrosion, stress, and failure delivering certified performance and best-in-class lifecycle integrity. Is your toughest project specified with corrosion-proof 904L round bars?