SS 321 WasherASTM A193 · ASME B18.22.1 · Manufacturer, stockist & exporter, India
AISI 321 · UNS S32100
An SS 321 washer is a flat or spring ring that spreads bolt load, made from SS 321 to ASTM A193 B8T. 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.
- ASTM A193
- 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 321 Washer?
- What it is
- A flat or spring ring that spreads bolt load
- Material
- ASTM A193 B8T
- Dimensions
- ASME B18.22.1 · DIN 125
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Washer Specification
| Product | SS 321 Washer |
|---|---|
| Material standard | ASTM A193 B8T |
| Dimensional standard | ASME B18.22.1 · DIN 125 |
| Sizes | M10 – M64 · ½" – 4" (others on request) |
| Threads | UNC · UN-8 · metric coarse |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
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
- Material to match the bolt
More on choosing: Washer guide.
SS 321 Washer: Why 321 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 321, 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 321 is picked for high-temperature service between 425 and 815 °C. |
|---|---|
| Typical service | Aircraft exhaust — Manifolds, bellows and exhaust systems. |
| Bolting | ASTM A193 B8T studs with A194 8T nuts |
SS 321 Washer Chemical Composition
| Element | Weight % |
|---|---|
| Chromium | 17.0 – 19.0 |
| Nickel | 9.0 – 12.0 |
| Titanium | 5 × (C + N) min, 0.70 max |
| Carbon | 0.08 max |
| Manganese | 2.00 max |
| Silicon | 0.75 max |
| Nitrogen | 0.10 max |
| Phosphorus | 0.045 max |
SS 321 Washer Mechanical Properties
| Annealed plate & sheet | Value |
|---|---|
| Tensile strength | 515 MPa · 75 ksi |
| Yield strength 0.2% | 205 MPa · 30 ksi |
| Elongation | 40% |
| Hardness | 217 HB max |
Full chemistry, properties and equivalents are on the SS 321 grade page.
Other SS 321 fasteners
SS 321 Washers for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 321 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 321 washers?
ASTM A194 8T heavy hex nuts.
Which standard covers SS 321 washers?
The material is ASTM A193 B8T; dimensions follow ASME B18.22.1 · DIN 125. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 321 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 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026