Nickel-iron-chromium alloy with molybdenum, copper and titanium (UNS N08825 / WNR 2.4858) is the material used to make Incoloy 825 Washers which are precision engineered fastening components. We design and make these washers to meet the highest international standards: ASTM B425 and ASME SB425 for the world's toughest industrial applications.
Incoloy 825 washers provide superior performance over conventional stainless steel and brass fasteners in an assortment of challenging environments, such as chemical processing units exposed to reducing acids, and offshore oil rigs in chlorinated seawater. As a result of their superior resistance to oxidizing and reducing corrosive media and high mechanical properties at high temperatures, they are the preferred material for engineers all over the world.
In India, Unifit Fastener is one of the most prominent Incoloy 825 Washer manufacturer and exporter where all the quality control measures are strictly adhered to, right from the raw material verification till rigorous hardness testing and dimensional testing and then certification. From our dedicated team we can deliver on time, every time, whether you need a standard flat washer (M6) or a custom machined UNS N08825 punched washer in 150mm.
Request a QuoteWhat Is Incoloy 825?
Incoloy 825 is a nickel-iron-chromium alloy (Ni: 38–46%, Cr: 19.5–23.5%) stabilized with titanium and further fortified with molybdenum (2.5–3.5%) and copper (1.5–3.0%). This special composition provides the alloy resistance to intergranular corrosion following welding or stress-relief annealing, making Incoloy 825 washers the material of choice where weld-zone integrity is a must.
Table of Content
- Specifications of Incoloy 825 Washers
- Chemical Composition Incoloy Alloy 825 Washers
- Mechanical Properties Incoloy Alloy 825 Washers
- Incoloy 825 Washers Equivalent Standards
- Types of Incoloy 825 Washers
- Technical Features & Benefits
- Applications of Incoloy 825 Washers
- Incoloy 825 vs. Competing Alloys
- Manufacturing Process & Quality Assurance
- Frequently Asked Questions
- Our Related Products
Specifications of Incoloy 825 Washers
| Parameter | Details |
| Material / Alloy | Incoloy 825 (UNS N08825 / WNR 2.4858) |
| Specifications | ASTM B425 / ASME SB425 |
| Standards | IS, BS, ASTM, DIN, JIS, GOST, AFNOR, EN |
| Size Range | M2 to M33 (Metric) | 3 mm to 200 mm (Custom sizes available) |
| Packaging | Boxes of 50 / 100 / 200 / Custom packaging |
| Finish | Self colour, Polished, Passivation |
| ASME Standard | ASME / ANSI B18.21.1 |
| DIN Standard | DIN 125A, DIN 127B, DIN 7980 |
| Thread Type | Coarse, Fine |
| Testing | Hardness test, Torsion test, Dimensional check |
Chemical Composition Incoloy Alloy 825 Washers
| Element | Ni | Cr | Fe | Mo | Ti | Al | Si | Cu | Mn | C |
| Min (%) | 38.0 | 19.5 | Balance | 2.5 | 0.6 | — | — | 1.5 | — | — |
| Max (%) | 46.0 | 23.5 | Balance | 3.5 | 1.2 | 0.2 | 0.5 | 3.0 | 1.0 | 0.05 |
Mechanical Properties Incoloy Alloy 825 Washers
| Property | Value (Imperial) | Value (Metric) |
| Tensile Strength | ≥ 80,000 psi | ≥ 550 MPa |
| Yield Strength (0.2% Offset) | 32,000 – 35,000 psi | 220 – 241 MPa |
| Elongation | 30% | 30% |
| Density | 8.14 g/cm³ | 8.14 g/cm³ |
| Melting Point | 2,550 °F | 1,400 °C |
| Hardness | ≤ 120 HBW | ≤ 120 HBW |
Incoloy 825 Washers Equivalent Standards
| Standard | Werkstoff Nr. | UNS | JIS | BS | GOST | AFNOR | EN |
| Incoloy 825 | 2.4858 | N08825 | NCF 825 | NA 16 | ЭП703 | NFE30C20DUM | NiCr21Mo |
Types of Incoloy 825 Washers
Unifit Fastener supplies the complete spectrum of Incoloy 825 Washer types to meet every application requirement:
Incoloy 825 Countersunk Washers
Incoloy 825 Dome Tooth Washers
Incoloy 825 Lock Washers
Incoloy 825 Machine Washers
Incoloy 825 Round Washers
Incoloy 825 Sealing Washers
Incoloy 825 Slot Washers
Incoloy 825 Spherical washers
Incoloy 825 Split Washers
Incoloy 825 Square Washers
Incoloy 825 Star Washers
Incoloy 825 Tab WashersTechnical Features & Benefits
Technical Features
- Excellent resistance to both reducing and oxidizing acids, including sulfuric, phosphoric, and organic acids
- Outstanding immunity to chloride-induced stress-corrosion cracking (Cl-SCC)
- Resistance to pitting and crevice corrosion in chloride-bearing media and seawater
- Titanium stabilization prevents sensitization (intergranular corrosion) after welding
- Maintains structural integrity from sub-zero temperatures up to 550°C
- Excellent formability — hot and cold working to complex geometries without property loss
Business Benefits
- Reduced maintenance shutdowns due to exceptional durability and fatigue resistance
- Lower total cost of ownership compared to more expensive superalloys in moderate-temperature service
- Test certificates (MTC) provided with every order for full traceability
- Custom sizes and finishes available — no minimum order quantity restrictions for bulk buyers
- Fast dispatch from Mumbai warehouse to global destinations within 3–7 business days
Applications of Incoloy 825 Washers
Incoloy 825 Washers from Unifit Fastener are deployed across a wide spectrum of critical industries where corrosion resistance and mechanical reliability are essential:
| Industry | Typical Application |
| Oil & Gas Refining | Flange connections, pressure vessel assemblies, offshore riser fasteners |
| Chemical Processing | Reactors, heat exchangers, acid pickling equipment, pump housings |
| Petrochemical Plants | High-pressure pipework, catalytic cracker assemblies, distillation columns |
| Nuclear Engineering | Containment vessel fasteners, cooling circuit assemblies |
| Marine & Offshore | Seawater desalination, subsea equipment, marine heat exchangers |
| Pollution Control | Flue gas desulfurization (FGD) scrubbers, waste treatment systems |
| Power Generation | Steam turbines, condenser tube sheets, boiler feed water systems |
| Pharmaceutical | Clean-room reactors, pharmaceutical manufacturing vessels |
| Food & Beverage | Hygienic processing equipment requiring acid-resistant fasteners |
| Pulp & Paper | Digester components, bleaching equipment, evaporator assemblies |
Incoloy 825 vs. Competing Alloys
| Property | Incoloy 825 | 316L SS | Monel 400 | Incoloy 800H |
| Ni Content | 38–46% | 10–14% | 63–70% | 30–35% |
| Cr Content | 19.5–23.5% | 16–18% | — | 19–23% |
| Max Service Temp. | 550°C | 425°C | 480°C | 980°C |
| Corrosion Resistance | Excellent | Good | Good | Very Good |
| Acid Resistance | Excellent (reducing + oxidizing) | Moderate | Good (reducing only) | Good |
| Seawater Resistance | Excellent | Moderate | Excellent | Moderate |
| Relative Cost | Moderate–High | Low | High | High |
| ASTM Standard | B425 | A193 | B164 | B408 |
Manufacturing Process & Quality Assurance
At Unifit Fastener, every Incoloy 825 Washer passes through a controlled, multi-stage manufacturing and quality assurance process before leaving our facility:
| Stage | Process / Check |
| 1. Raw Material Inspection | Chemical composition verification via spectrometric analysis (PMI testing) |
| 2. Forging / Cold Forming | Precision tooling ensures dimensional accuracy across all washer geometries |
| 3. Heat Treatment | Solution annealing to relieve residual stress and optimize corrosion resistance |
| 4. Machining (where applicable) | CNC machining for tight-tolerance custom washer profiles |
| 5. Surface Finishing | Self-colour, polished, or passivated finish per customer specification |
| 6. Dimensional Inspection | 100% dimensional verification against ASTM / DIN / BS drawing standards |
| 7. Mechanical Testing | Hardness (HBW), tensile strength, and torsion testing per batch |
| 8. Certification | Mill Test Certificates (MTC) per EN 10204 3.1 / 3.2 issued with every order |
Certifications & Standards Compliance
- ISO 9001:2015 Quality Management System certified
- ASTM B425 / ASME SB425 compliant material
- EN 10204 3.1 and 3.2 Mill Test Certificates available
- DIN 125A, DIN 127B, DIN 7980 dimensional standards
- ASME / ANSI B18.21.1 standard compliant
- Third-party inspection available from DNV, Bureau Veritas, TÜV, SGS
Our Related Products
Frequently Asked Questions (FAQs)
These terms refer to the same alloy — UNS N08825. 'Incoloy 825' is the trademarked brand name used by Special Metals Corporation, while 'Inconel 825' is a common market term. Chemically and mechanically, they are identical. Unifit Fastener supplies washers to UNS N08825 specifications regardless of the trade name used.
Incoloy 825 Washers are manufactured to ASTM B425 (Bar, Rod, and Wire) and ASME SB425. Dimensional standards include DIN 125A, DIN 127B, DIN 7980, and ASME/ANSI B18.21.1 depending on the washer type and end-use requirement.
We supply Incoloy 825 Washers in metric sizes from M2 to M33 and diameter sizes from 3 mm to 200 mm. Custom oversized and non-standard geometries are available on request with no minimum order restriction for bulk quantities.
Yes. The molybdenum and copper additions in Incoloy 825 provide excellent resistance to pitting and crevice corrosion in seawater and brine environments. They are widely used in marine, offshore, and desalination plant applications where stainless steel fasteners fail prematurely.