SS 321 NippleASTM A182 · MSS SP-95 · Manufacturer, trader & exporter, India
AISI 321 · UNS S32100
An SS 321 nipple is a short length of pipe, threaded or plain, used to connect fittings, made from SS 321 to ASTM A182 F321. Pipe nipples connect valves and fittings in small-bore lines. Swage nipples (MSS SP-95) also change size between their two ends.
- ASTM A182
- MSS SP-95
- 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 Nipple?
- What it is
- A short length of pipe, threaded or plain, used to connect fittings
- Material
- ASTM A182 F321
- Dimensions
- MSS SP-95 · ASME B36.10 / B36.19
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Nipple Specification
| Product | SS 321 Nipple |
|---|---|
| Material standard | ASTM A182 F321 |
| Dimensional standard | MSS SP-95 · ASME B36.10 / B36.19 |
| Sizes | ⅛" – 4" (ASME B16.11) |
| Wall / class | Class 2000 / 3000 / 6000 / 9000 |
| Ends | Socket weld · NPT threaded |
| 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 Nipple
Pipe nipples connect valves and fittings in small-bore lines. Swage nipples (MSS SP-95) also change size between their two ends.
- Close, short and long lengths
- Swage nipples to MSS SP-95
- Threaded both ends, one end, or plain
More on choosing: Nipple guide.
SS 321 Nipple: Why 321 for nipples
Pipe nipples connect valves and fittings in small-bore lines. Swage nipples (MSS SP-95) also change size between their two ends. 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 fittings keep the line clean and corrosion-free. SS 321 is picked for high-temperature service between 425 and 815 °C. |
|---|---|
| Typical service | Aircraft exhaust — Manifolds, bellows and exhaust systems. |
| Welding to carbon steel | ER309L (or E309L electrode) is the usual filler when joining it to carbon steel |
| Matching filler | ER347 (AWS A5.9) |
SS 321 Nipple 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 Nipple 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 pipe fittings
SS 321 Nipple — questions buyers ask
What is a swage nipple?
A nipple that reduces from one size to another, concentric or eccentric, to MSS SP-95.
Can SS 321 nipples be welded to carbon steel?
Yes — ER309L (or E309L electrode) is the usual filler when joining it to carbon steel.
Which standard covers SS 321 nipples?
The material is ASTM A182 F321; dimensions follow MSS SP-95 · ASME B36.10 / B36.19. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 321 nipple?
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 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