Nickel Alloy Flat Washers
| Standard | DIN 125 · ISO 7089 · ASTM B446 / ASTM B637 material ref |
|---|---|
| Material | Inconel 625 / Inconel 718 |
| Strength Grade | — |
| Size Range | M8-M48 |
| Surface Treatment | Pickled / Passivated |
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Product Description
Product Description & Key Specifications
Nickel alloy flat washers are used with nickel alloy bolts, stud bolts and nuts in corrosive, high-temperature and offshore environments where ordinary stainless or carbon steel washers may not provide sufficient material compatibility. This range includes Inconel 625 and Inconel 718 with ISO 7089 / DIN 125 washer references and ASTM B446 / ASTM B637 material references.
Inconel 625 is commonly selected for chloride, seawater, offshore and chemical corrosion resistance. Inconel 718 is selected where higher strength and temperature capability are required according to the project specification. Washer material should match the bolt and nut alloy when galvanic or corrosion compatibility is critical.
M8-M48 washers are supplied with pickled and passivated finish to improve surface cleanliness after machining or forming. RFQs should confirm alloy grade, washer dimensions, finish, PMI requirement, NACE or project corrosion requirements, certificate level and whether matching nickel alloy studs or nuts are needed.
| Product type | Nickel alloy flat washers / Inconel washers |
|---|---|
| Standards | ISO 7089 / DIN 125 / ASTM B446 material reference / ASTM B637 material reference |
| Material | Inconel 625 / Inconel 718 |
| Strength grade | Alloy 625 / Alloy 718 material condition by project specification |
| Size range | M8-M48 |
| Common models | M8, M10, M12, M16, M20, M24, M30, M36, M42, M48 |
| Washer form | Flat washer, standard or drawing-based ID / OD / thickness |
| Surface finish | Pickled / Passivated |
| Matched hardware | Nickel alloy stud bolts, nickel alloy hex nuts and corrosion-resistant bolting assemblies |
| Documentation | MTC, PMI, CoC, dimensional report and passivation report on request |
Dimensions & SpecificationsDIN 125A / ISO 7089
Technical Drawing
Dimensional Table
| Parameter | Φ1.6 | Φ1.7 | Φ2 | Φ2.3 | Φ2.5 | Φ2.6 | Φ3 | Φ3.5 | Φ4 | Φ5 | Φ6 | Φ7 | Φ8 | Φ10 | Φ12 | Φ14 | Φ16 | Φ18 | Φ20 | Φ22 | Φ24 | Φ26 | Φ27 | Φ28 | Φ30 | Φ32 | Φ33 | Φ35 | Φ36 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| d/min | 1.7 | 1.8 | 2.2 | 2.5 | 2.7 | 2.8 | 3.2 | 3.7 | 4.3 | 5.3 | 6.4 | 7.4 | 8.4 | 10.5 | 13 | 15 | 17 | 19 | 21 | 23 | 25 | 27 | 28 | 29 | 31 | 33 | 34 | 36 | 37 |
| d/max | 1.84 | 1.94 | 2.34 | 2.64 | 2.84 | 2.94 | 3.38 | 3.88 | 4.48 | 5.48 | 6.62 | 7.62 | 8.62 | 10.77 | 13.27 | 15.27 | 17.27 | 19.33 | 21.33 | 23.33 | 25.33 | 27.33 | 28.33 | 29.33 | 31.39 | 33.62 | 34.62 | 36.62 | 37.62 |
| dc/max | 4 | 4.5 | 5 | 6 | 6 | 7 | 7 | 8 | 9 | 10 | 12 | 14 | 16 | 20 | 24 | 28 | 30 | 34 | 37 | 39 | 44 | 50 | 50 | 50 | 56 | 60 | 60 | 66 | 66 |
| dc/min | 3.7 | 4.2 | 4.7 | 5.7 | 5.7 | 6.64 | 6.64 | 7.64 | 8.64 | 9.64 | 11.57 | 13.57 | 15.57 | 19.48 | 23.48 | 27.48 | 29.48 | 33.38 | 36.38 | 38.38 | 43.38 | 49.38 | 49.38 | 49.38 | 55.26 | 58.8 | 58.8 | 64.8 | 64.8 |
| h/max | 0.35 | 0.35 | 0.35 | 0.55 | 0.55 | 0.55 | 0.55 | 0.55 | 0.9 | 1.1 | 1.8 | 1.8 | 1.8 | 2.2 | 2.7 | 2.7 | 3.3 | 3.3 | 3.3 | 3.3 | 4.3 | 4.3 | 4.3 | 4.3 | 4.3 | 5.6 | 5.6 | 5.6 | 5.6 |
| h/min | 0.25 | 0.25 | 0.25 | 0.45 | 0.45 | 0.45 | 0.45 | 0.45 | 0.7 | 0.9 | 1.4 | 1.4 | 1.4 | 1.8 | 2.3 | 2.3 | 2.7 | 2.7 | 2.7 | 2.7 | 3.7 | 3.7 | 3.7 | 3.7 | 3.7 | 4.4 | 4.4 | 4.4 | 4.4 |
Engineering references
Technical resources
Review the applicable dimensions, drawing and standard relationship before confirming the ordered specification.02
Selection
Selection Advantages by Application
Offshore and Subsea Bolting
Inconel 625 washers are used with nickel alloy studs and nuts in offshore structures, subsea equipment and seawater-exposed assemblies where chloride corrosion resistance is required.
Oil and gas fastenersHigh-Temperature Equipment
Inconel 718 washers can be specified for high-strength and elevated-temperature bolting packages when the project requires compatible nickel alloy hardware.
Power generation fastenersRenewable Energy and Marine Equipment
Nickel alloy washers support marine renewable equipment, offshore wind auxiliaries and corrosive outdoor assemblies where stainless steel may not be sufficient.
Renewable energy fasteners03
Assembly
Recommended Matching Products
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Manufacturing
Manufacturing & Quality Control
Manufacturing CapabilityQuality Control
Machining, stamping or waterjet cutting from nickel alloy stockInconel 625 / 718 material certificate and heat number verification
Standard ISO / DIN or drawing-based washer dimensionsID, OD, thickness, flatness and edge quality inspection
Pickling and passivation for nickel alloy surface conditionSurface cleanliness, visual inspection and PMI support when specified
Washer supply alone or as nickel alloy bolting packagesAssembly compatibility with studs and nuts reviewed by alloy and size
Export packaging by alloy, heat and sizeMTC, PMI, CoC and inspection report prepared on request
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FAQ
Common Questions Before RFQ
When should nickel alloy flat washers be used?
Use them when the bolting assembly requires corrosion-resistant or high-temperature nickel alloy compatibility, especially with Inconel studs and nuts.
What is the difference between Inconel 625 and Inconel 718 washers?
Inconel 625 is often selected for corrosion resistance, especially chloride and seawater exposure. Inconel 718 is used where higher strength and elevated-temperature performance are specified.
Can PMI be supplied?
Yes. PMI, material certificates, CoC and dimensional inspection reports can be supplied when required by the project.
Are these washers passivated?
Pickled and passivated finish is available to improve surface condition after manufacturing.
Can matching nickel alloy nuts and studs be supplied?
Yes. Washers can be supplied with matching nickel alloy stud bolts and hex nuts by alloy, size, finish and certificate scope.
Need Inconel flat washers for severe service bolting?
Send alloy grade, washer size, drawing, finish, quantity, PMI and certificate requirements. We can quote Inconel 625 / 718 washers alone or with matching nickel alloy stud bolts and nuts.
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