SS 310 / 310S WasherUNS S31008 · ASME B18.22.1 · Manufacturer, trader & exporter, India
AISI 310S · UNS S31008
An SS 310 / 310S washer is a flat or spring ring that spreads bolt load. Finished fastener specification not asserted; material and manufacturing route not asserted — alloy (UNS S31008), 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 S31008
- 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 310 / 310S Washer?
- What it is
- A flat or spring ring that spreads bolt load
- Finished spec
- Not asserted
- Material / feedstock
- Not asserted — alloy (UNS S31008), dimensions and finished requirements are to the purchase specification
- Dimensions
- ASME B18.22.1 · DIN 125 (legacy DIN)
- Grade
- SS 310 / 310S · UNS S31008
- Best at
- Furnaces, burners and heat treatment at high temperature
SS 310 / 310S Washer Specification
| Product | SS 310 / 310S Washer |
|---|---|
| Finished fastener specification | Not asserted |
| Material / feedstock specification | Not asserted — alloy (UNS S31008), 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 310 / 310S Washer: Why 310S 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 310 / 310S, 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 310 / 310S is picked for furnaces, burners and heat treatment at high temperature. |
|---|---|
| Typical service | Furnace parts — Muffles, retorts, radiant tubes and conveyor belts. |
| Bolting | A193 B8 or project-specified bolting |
SS 310 / 310S 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 |
| Phosphorus | As specified |
| Sulphur | As specified |
| Iron | 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 S31008.
SS 310 / 310S 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 S31008 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 310 / 310S grade page.
Standards on this page
Other SS 310 / 310S fasteners
SS 310 / 310S 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 310 / 310S washers?
Usually a nut in the same alloy — it may be machined from ASTM A276 / A479 bar, where applicable; finished requirements are to the purchase specification or project drawing.
Which standard covers SS 310 / 310S washers?
Finished fastener specification: Not asserted. Material / feedstock: Not asserted — alloy (UNS S31008), 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 310 / 310S 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