SS 304L WasherUNS S30403 · ASME B18.22.1 · Manufacturer, trader & exporter, India
AISI 304L · UNS S30403
An SS 304L washer is a flat or spring ring that spreads bolt load. Finished fastener specification not asserted; material and manufacturing route not asserted — alloy (UNS S30403), 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 S30403
- 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 304L Washer?
- What it is
- A flat or spring ring that spreads bolt load
- Finished spec
- Not asserted
- Material / feedstock
- Not asserted — alloy (UNS S30403), dimensions and finished requirements are to the purchase specification
- Dimensions
- ASME B18.22.1 · DIN 125 (legacy DIN)
- Grade
- SS 304L · UNS S30403
- Best at
- Welded tanks, piping and vessels in general corrosive service
SS 304L Washer Specification
| Product | SS 304L Washer |
|---|---|
| Finished fastener specification | Not asserted |
| Material / feedstock specification | Not asserted — alloy (UNS S30403), 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 304L Washer: Why 304L 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 304L, 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 304L is picked for welded tanks, piping and vessels in general corrosive service. |
|---|---|
| Typical service | Process piping — Welded lines in chemical and pharma plants. |
| Bolting | ASTM A193 B8 studs with A194 8 nuts |
SS 304L 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 S30403.
SS 304L 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 S30403 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 304L grade page.
Standards on this page
Other SS 304L fasteners
SS 304L 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 304L washers?
ASTM A194 8 heavy hex nuts.
Which standard covers SS 304L washers?
Finished fastener specification: Not asserted. Material / feedstock: Not asserted — alloy (UNS S30403), 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 304L 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