SS 304 WasherUNS S30400 · ASME B18.22.1 · Manufacturer, trader & exporter, India
AISI 304 · UNS S30400
An SS 304 washer is a flat or spring ring that spreads bolt load. Finished fastener specification not asserted; material and manufacturing route not asserted — alloy (UNS S30400), dimensions and finished requirements are to the purchase specification. Flat washers protect the joint surface and spread load; spring and lock washers resist loosening. Match the washer material to the bolt to avoid galvanic corrosion.
- UNS S30400
- ASME B18.22.1
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an SS 304 Washer?
- What it is
- A flat or spring ring that spreads bolt load
- Finished spec
- Not asserted
- Material / feedstock
- Not asserted — alloy (UNS S30400), dimensions and finished requirements are to the purchase specification
- Dimensions
- ASME B18.22.1 · DIN 125 (legacy DIN)
- Grade
- SS 304 · UNS S30400
- Best at
- General corrosion resistance, food, water and architectural work
SS 304 Washer Specification
| Product | SS 304 Washer |
|---|---|
| Finished fastener specification | Not asserted |
| Material / feedstock specification | Not asserted — alloy (UNS S30400), dimensions and finished requirements are to the purchase specification |
| Dimensional standard | ASME B18.22.1 · DIN 125 (legacy DIN) |
| Manufacturing route | Not asserted |
| Project / purchase specification | Yes — finished fastener requirements are to the purchase specification or project drawing |
| Sizes | To suit M10 – M64 · ½" – 4" bolts (others on request) |
| Testing | PMI (as specified in the PO) · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
When to Choose a Washer
Flat washers protect the joint surface and spread load; spring and lock washers resist loosening. Match the washer material to the bolt to avoid galvanic corrosion.
- Flat, spring and lock
- ASME B18.21.1 · DIN 125 / 127 (legacy DIN)
- Material to match the bolt
More on choosing: Washer guide.
SS 304 Washer: Why 304 for washers
Flat washers protect the joint surface and spread load; spring and lock washers resist loosening. Match the washer material to the bolt to avoid galvanic corrosion. In SS 304, the choice usually comes down to the medium and temperature — the rows here are the points buyers check for this exact combination.
| Why this grade | Stainless fasteners resist atmospheric and process corrosion. SS 304 is picked for general corrosion resistance, food, water and architectural work. |
|---|---|
| Typical service | Food & dairy — Tanks, piping and equipment that must be cleaned daily. |
| Bolting | ASTM A193 B8 studs with A194 8 nuts |
SS 304 Washer Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A240 for UNS S30400.
SS 304 Washer Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
| Hardness | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A240 for UNS S30400 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 304 grade page.
Standards on this page
Other SS 304 fasteners
SS 304 Washer — questions buyers ask
Do I need washers on flange bolting?
Many specifications require through-hardened washers under nuts for controlled tightening; follow the project bolting spec.
What nut is used with SS 304 washers?
ASTM A194 8 heavy hex nuts.
Which standard covers SS 304 washers?
Finished fastener specification: Not asserted. Material / feedstock: Not asserted — alloy (UNS S30400), dimensions and finished requirements are to the purchase specification. Dimensions: ASME B18.22.1 · DIN 125 (legacy DIN). State the finished specification, material and dimensions on your purchase order or project drawing.
What decides the price of a SS 304 washer?
The alloy price, the size and dimensions, quantity, and the testing and documents required. Send your list and we quote the same working day.
What documents do you supply?
EN 10204 3.1 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026