SS 321 Hex BoltASTM A193 · ASME B18.2.1 · Manufacturer, trader & exporter, India
AISI 321 · UNS S32100
An SS 321 hex bolt is a bolt with a hexagonal head. ASTM A193 B8T where specified; confirm grade and class in the purchase specification. Hex bolts join flanges, structures and equipment where one side is accessible for the head. Dimensions to ASME B18.2.1, or DIN 931 / 933 (legacy DIN) where an older specification calls for them.
- ASTM A193
- ASME B18.2.1
- 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 Hex Bolt?
- What it is
- A bolt with a hexagonal head
- Finished spec
- ASTM A193 B8T where specified
- Material / feedstock
- Within the finished specification (A193 B8T)
- Dimensions
- ASME B18.2.1 · DIN 931 / 933 (legacy DIN)
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Hex Bolt Specification
| Product | SS 321 Hex Bolt |
|---|---|
| Finished fastener specification | ASTM A193 B8T where specified |
| Material / feedstock specification | Within the finished specification (A193 B8T) |
| Dimensional standard | ASME B18.2.1 · DIN 931 / 933 (legacy DIN) |
| Manufacturing route | To the finished specification and purchase specification |
| Project / purchase specification | Yes — finished fastener requirements are to the purchase specification or project drawing |
| Sizes | M10 – M64 · ½" – 4" (others on request) |
| Threads | UNC · UN-8 · metric coarse |
| 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 Hex Bolt
Hex bolts join flanges, structures and equipment where one side is accessible for the head. Dimensions to ASME B18.2.1, or DIN 931 / 933 (legacy DIN) where an older specification calls for them.
- Partially or fully threaded
- ASME B18.2.1 / DIN 931 / DIN 933
- Supplied with nuts and washers
More on choosing: Hex bolt guide.
SS 321 Hex Bolt: Why 321 for hex bolts
Hex bolts join flanges, structures and equipment where one side is accessible for the head. Dimensions to ASME B18.2.1, or DIN 931 / 933 (legacy DIN) where an older specification calls for them. 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 Hex Bolt Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | As specified |
| Titanium | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | As specified |
| Phosphorus | 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 S32100.
SS 321 Hex Bolt 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 S32100 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 321 grade page.
Other SS 321 fasteners
SS 321 Hex Bolt — questions buyers ask
DIN 931 or DIN 933?
DIN 931 bolts are partly threaded; DIN 933 are fully threaded.
What nut is used with SS 321 hex bolts?
ASTM A194 8T heavy hex nuts.
Which standard covers SS 321 hex bolts?
Finished fastener specification: ASTM A193 B8T where specified. Material / feedstock: Within the finished specification (A193 B8T). Dimensions: ASME B18.2.1 · DIN 931 / 933 (legacy DIN). State the finished specification, material and dimensions on your purchase order or project drawing.
What decides the price of a SS 321 hex bolt?
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