SS 321 CouplingASTM A182 · ASME B16.11 · Manufacturer, stockist & exporter, India
AISI 321 · UNS S32100
An SS 321 coupling is a short forged fitting that joins two pipes, made from SS 321 to ASTM A182 F321. Full couplings join two pipes; half couplings are welded to a pipe or vessel as a branch connection. Socket-weld or threaded to ASME B16.11.
- ASTM A182
- ASME B16.11
- 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 Coupling?
- What it is
- A short forged fitting that joins two pipes
- Material
- ASTM A182 F321
- Dimensions
- ASME B16.11
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Coupling Specification
| Product | SS 321 Coupling |
|---|---|
| Material standard | ASTM A182 F321 |
| Dimensional standard | ASME B16.11 |
| Sizes | ⅛" – 4" (ASME B16.11) |
| Wall / class | Class 2000 / 3000 / 6000 / 9000 |
| Ends | Socket weld · NPT threaded |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose a Coupling
Full couplings join two pipes; half couplings are welded to a pipe or vessel as a branch connection. Socket-weld or threaded to ASME B16.11.
- Full and half couplings
- Reducing couplings
- Class 3000 / 6000 / 9000
SS 321 Coupling 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 Coupling 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 pipe fittings
SS 321 Coupling — questions buyers ask
What is a half coupling used for?
It is welded onto a pipe or vessel to create a small threaded or socket-weld branch.
Which standard covers SS 321 couplings?
The material is ASTM A182 F321; dimensions follow ASME B16.11. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 321 coupling?
The alloy price, the size and schedule or class, 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