At Ananka Fasteners Pvt Ltd, we engineer, manufacture, and supply premium SS 904L (UNS N08904) Flat Washer built for demanding service. Super-austenitic stainless with high nickel and molybdenum for resistance to sulphuric acid and chloride environments. This technical datasheet covers the precise dimensional tolerances per DIN 125 and the material requirements dictated by ASTM A276 / B649.
A SS 904L Flat Washer distributes fastener load evenly across a joint while resisting the fretting and corrosion that carbon-steel washers are prone to in marine, electrical and outdoor service. The tables below provide the principal dimensions, equivalent material grades, chemical composition and mechanical properties covered by the technical data for this product.
Our flat washers are manufactured in standard and custom configurations, ensuring a precise fit for demanding structural, piping, and chemical-process applications.
| Product Name | SS 904L Flat Washer | Material Category | Stainless Steel |
| Material Grade | SS 904L (UNS N08904) | Fastener Spec | ASTM A276 / B649 |
| Dimension Spec | DIN 125 | Material Spec | ASTM A276 / B649 |
| Thread Standard | N/A (Plain Washer) | Thread Tolerance | Inside-diameter tolerance per standard |
The DIN 125 specification governs the physical geometry of this product. The tolerances below ensure a secure, reliable mate under service loads. DIN 125 Form A governs metric plain (flat) washers with a chamfered edge.
| Nominal Size (for bolt) | Inside Diameter d1 (mm) | Outside Diameter d2 (mm) | Thickness s (mm) |
|---|---|---|---|
| M6 | 6.4 | 12.0 | 1.6 |
| M8 | 8.4 | 16.0 | 1.6 |
| M10 | 10.5 | 20.0 | 2.0 |
| M12 | 13.0 | 24.0 | 2.5 |
| M16 | 17.0 | 30.0 | 3.0 |
| M20 | 21.0 | 37.0 | 3.0 |
| M24 | 25.0 | 44.0 | 4.0 |
This dimensional series carries a chamfered outer edge and is the standard flat washer configuration for general assembly. Buyers should confirm the required nominal diameter, inside-diameter clearance class and outside diameter against the purchase drawing or applicable standard before ordering.
The UNS N08904 Flat Washer is manufactured from SS 904L, a stainless steel. The equivalent designations below assist with cross-referencing this material against European, British and other national standards.
| US / UNS | Werkstoff Nr. (DIN) | European (EN) | British Standard (BS) | Other / AFNOR |
|---|---|---|---|---|
| N08904 | 1.4539 | X1NiCrMoCu25-20-5 | 904 S13 | Z2 NCDU 25-20 (AFNOR) |
This section details the chemical composition limits and minimum mechanical properties governing SS 904L (UNS N08904) fasteners, as dictated by ASTM A276 / B649 (chemistry & mechanicals) and the raw bar/rod standard ASTM A276 / B649.
| Element | Composition, % |
|---|---|
| Chromium | 19.0–23.0 |
| Nickel | 23.0–28.0 |
| Molybdenum | 4.0–5.0 |
| Copper | 1.0–2.0 |
| Carbon, max | 0.020 |
| Manganese, max | 2.0 |
| Silicon, max | 1.0 |
| Iron | Balance |
| Condition / Temper | Tensile Strength min, psi (MPa) | Yield Strength min, psi (MPa) | Elongation min, % | Hardness |
|---|---|---|---|---|
| Annealed bar | 71 000 (490) | 31 000 (215) | 35 | – |
Our SS 904L flat washers are specified across the following industries and service conditions, drawing on the material’s core strengths:
For applications exposed to highly aggressive chemicals or chloride-rich environments, the exact operating conditions should be reviewed against the certified data for this grade rather than general stainless steel assumptions.
Every batch of Flat Washers produced undergoes rigorous internal and third-party testing to ensure zero-defect delivery. We supply complete traceability with our global shipments.
For technical documentation and quotations, buyers can also review the Ananka Fasteners manufacturing and supply range or contact the team through the fastener enquiry and technical support page.
This datasheet references DIN 125 for dimensional requirements and ASTM A276 / B649 for material and fastener requirements. The applicable standard edition and purchase requirements should be confirmed for every project.
For DIN standards information, see the DIN standards catalogue. For ASTM International material and fastener specifications, see the ASTM International standards catalogue. These external references are provided for standards identification; the purchaser should verify the current edition applicable to the order.
A SS 904L Flat Washer is a plain load-distribution washer manufactured from SS 904L (UNS N08904). The product combines the DIN 125 dimensional geometry with the ASTM A276 / B649 material and fastener requirements.
The dimensional information in this datasheet is based on DIN 125, which governs the physical geometry of this product. The table above provides the principal dimensions listed for the SS 904L product range.
SS 904L is identified as UNS N08904. The equivalent designations listed in this datasheet include Werkstoff Nr. 1.4539, EN X1NiCrMoCu25-20-5, British Standard 904 S13, Z2 NCDU 25-20 (AFNOR).
SS 904L is a stainless steel known for good general corrosion resistance and wide industrial availability. For applications exposed to highly aggressive chemicals or chloride-rich environments, the exact operating conditions should be reviewed against the certified data for this grade rather than general stainless steel assumptions.
The product information supports standard and custom configurations. For a quotation, provide the required material grade, nominal size, dimensional requirement, quantity, standard and any inspection or certificate requirements.
Need a SS 904L Flat Washer for an industrial project? Send the required size, quantity, standard and certification requirements to Ananka Fasteners. Our team can review the requirement and provide technical and commercial information for standard or custom configurations.
Recommended RFQ details: SS 904L / UNS N08904, nominal size, DIN 125 requirement, quantity, inspection requirements and EN 10204 certificate requirements where applicable.
