SS 321 LateralASTM A403 · MSS SP-43 / manufacturer standard · Manufacturer, trader & exporter, India
AISI 321 · UNS S32100
An SS 321 lateral is a fitting with a 45° branch, made from SS 321 to ASTM A403 WP321. Laterals bring in a branch at 45°, reducing turbulence and pressure drop compared to a tee. Common in drainage, slurry and process lines.
- ASTM A403
- MSS SP-43 / manufacturer standard
- 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 Lateral?
- What it is
- A fitting with a 45° branch
- Material
- ASTM A403 WP321
- Dimensions
- MSS SP-43 / manufacturer standard
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Lateral Specification
| Product | SS 321 Lateral |
|---|---|
| Material standard | ASTM A403 WP321 |
| Dimensional standard | MSS SP-43 / manufacturer standard |
| Sizes | ½" – 48" |
| Wall / class | Sch 5S – XXS, to match pipe |
| 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 Lateral
Laterals bring in a branch at 45°, reducing turbulence and pressure drop compared to a tee. Common in drainage, slurry and process lines.
- 45° branch
- Equal and reducing
- Often fabricated
More on choosing: Lateral guide.
SS 321 Lateral: Why 321 for laterals
Laterals bring in a branch at 45°, reducing turbulence and pressure drop compared to a tee. Common in drainage, slurry and process lines. 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 Lateral 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 Lateral 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 Lateral — questions buyers ask
When is a lateral better than a tee?
Where lower turbulence matters — slurries, solids and gravity drainage.
Can SS 321 laterals 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 laterals?
The material is ASTM A403 WP321; dimensions follow MSS SP-43 / manufacturer standard. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 321 lateral?
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