SS 321 TeeASTM A403 · ASME B16.9 · Manufacturer, trader & exporter, India
AISI 321 · UNS S32100
An SS 321 tee is a fitting with a 90° branch that splits or combines flow, made from SS 321 to ASTM A403 WP321 (buttweld) · ASTM A182 F321 (forged). Equal tees have the same size branch as the run; reducing tees have a smaller branch. Barred tees add internal bars so pipeline pigs pass the branch.
- 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 Tee?
- What it is
- A fitting with a 90° branch that splits or combines flow
- 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 Tee Specification
| Product | SS 321 Tee |
|---|---|
| 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 a Tee
Equal tees have the same size branch as the run; reducing tees have a smaller branch. Barred tees add internal bars so pipeline pigs pass the branch.
- Equal and reducing
- Barred tees for piggable lines
- Buttweld, socket weld or threaded
More on choosing: Tee guide.
SS 321 Tee: Why 321 for tees
Equal tees have the same size branch as the run; reducing tees have a smaller branch. Barred tees add internal bars so pipeline pigs pass the branch. 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 Tee 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 Tee 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 Tee dimensions — ASME B16.9
Values in mm, the same for every material; the wall thickness matches the pipe schedule.
| NPS | OD | Tee centre-to-end C |
|---|---|---|
| ½" | 21.3 | 25 |
| ¾" | 26.7 | 29 |
| 1" | 33.4 | 38 |
| 1½" | 48.3 | 57 |
| 2" | 60.3 | 64 |
| 3" | 88.9 | 86 |
| 4" | 114.3 | 105 |
| 6" | 168.3 | 143 |
| 8" | 219.1 | 178 |
| 10" | 273.1 | 216 |
| 12" | 323.9 | 254 |
| 16" | 406.4 | 305 |
| 20" | 508.0 | 381 |
| 24" | 610.0 | 432 |
Full chart: ASME B16.9 fitting dimensions.
SS 321 Tee — questions buyers ask
What is a barred tee?
A tee with bars welded across the branch opening so a pipeline pig cannot enter the branch.
Can SS 321 tees 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 tees?
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 tee?
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