SS 321 ElbowASTM A403 · ASME B16.9 · Manufacturer, trader & exporter, India
AISI 321 · UNS S32100
An SS 321 elbow is a fitting that changes the direction of a pipe run, made from SS 321 to ASTM A403 WP321 (buttweld) · ASTM A182 F321 (forged). Elbows come in 45°, 90° and 180° (return) angles. Long-radius (1.5D) is the default for flow; short-radius (1D) saves space. Buttweld elbows follow ASME B16.9; socket-weld and threaded elbows follow ASME B16.11.
- ASTM A403
- ASME B16.9
- 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 Elbow?
- What it is
- A fitting that changes the direction of a pipe run
- Material
- ASTM A403 WP321 (buttweld) · ASTM A182 F321 (forged)
- Dimensions
- ASME B16.9 · B16.11
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Elbow Specification
| Product | SS 321 Elbow |
|---|---|
| Material standard | ASTM A403 WP321 (buttweld) · ASTM A182 F321 (forged) |
| Dimensional standard | ASME B16.9 · B16.11 |
| Sizes | Buttweld ½" – 48" · forged ⅛" – 4" |
| Wall / class | Schedule to match pipe · Class 3000 / 6000 (forged) |
| Ends | Bevelled to ASME B16.25 |
| 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 an Elbow
Elbows come in 45°, 90° and 180° (return) angles. Long-radius (1.5D) is the default for flow; short-radius (1D) saves space. Buttweld elbows follow ASME B16.9; socket-weld and threaded elbows follow ASME B16.11.
- LR (1.5D) and SR (1D) radius
- 45°, 90° and 180° return
- Seamless or welded construction
More on choosing: Elbow guide.
SS 321 Elbow: Why 321 for elbows
Elbows come in 45°, 90° and 180° (return) angles. Long-radius (1.5D) is the default for flow; short-radius (1D) saves space. Buttweld elbows follow ASME B16.9; socket-weld and threaded elbows follow ASME B16.11. 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 Elbow 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 Elbow 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 Elbow dimensions — ASME B16.9
Values in mm, the same for every material; the wall thickness matches the pipe schedule.
| NPS | OD | 90° LR elbow A | 45° elbow B | 90° SR elbow |
|---|---|---|---|---|
| ½" | 21.3 | 38 | 16 | — |
| ¾" | 26.7 | 38 | 19 | — |
| 1" | 33.4 | 38 | 22 | 25 |
| 1½" | 48.3 | 57 | 29 | 38 |
| 2" | 60.3 | 76 | 35 | 51 |
| 3" | 88.9 | 114 | 51 | 76 |
| 4" | 114.3 | 152 | 64 | 102 |
| 6" | 168.3 | 229 | 95 | 152 |
| 8" | 219.1 | 305 | 127 | 203 |
| 10" | 273.1 | 381 | 159 | 254 |
| 12" | 323.9 | 457 | 190 | 305 |
| 16" | 406.4 | 610 | 254 | 406 |
| 20" | 508.0 | 762 | 318 | 508 |
| 24" | 610.0 | 914 | 381 | 610 |
Full chart: ASME B16.9 fitting dimensions.
SS 321 Elbow — questions buyers ask
Long radius or short radius elbow?
Long radius gives lower pressure drop and is the default. Short radius is used where space is tight, with a small pressure-rating reduction per ASME B16.9.
Can SS 321 elbows 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 elbows?
The material is ASTM A403 WP321 (buttweld) · ASTM A182 F321 (forged); dimensions follow ASME B16.9 · 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 elbow?
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