SS 321 Stub EndASTM A403 · ASME B16.9 · Manufacturer, stockist & exporter, India
AISI 321 · UNS S32100
An SS 321 stub end is a short pipe length with a flared lap that works with a lap joint flange, made from SS 321 to ASTM A403 WP321. Stub ends are welded to the pipe and backed by a loose lap joint flange. Type A (long pattern, ASME B16.9) and short-pattern MSS SP-43 stub ends are the common choices.
- 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 Stub End?
- What it is
- A short pipe length with a flared lap that works with a lap joint flange
- Material
- ASTM A403 WP321
- Dimensions
- ASME B16.9 · MSS SP-43
- Grade
- SS 321 · UNS S32100
- Best at
- High-temperature service between 425 and 815 °C
SS 321 Stub End Specification
| Product | SS 321 Stub End |
|---|---|
| Material standard | ASTM A403 WP321 |
| Dimensional standard | ASME B16.9 · MSS SP-43 |
| Sizes | ½" – 48" |
| Wall / class | Sch 5S – XXS, to match pipe |
| Ends | Bevelled to ASME B16.25 |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose a Stub End
Stub ends are welded to the pipe and backed by a loose lap joint flange. Type A (long pattern, ASME B16.9) and short-pattern MSS SP-43 stub ends are the common choices.
- Long pattern (ASME B16.9) and short pattern (MSS SP-43)
- Type A, B and C lap designs
- Used with a carbon-steel backing flange to save alloy
SS 321 Stub End 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 Stub End 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 Stub End — questions buyers ask
Long or short stub end?
Long-pattern stub ends to ASME B16.9 suit most piping; short-pattern MSS SP-43 stub ends save alloy and space in low-pressure lines.
Which standard covers SS 321 stub ends?
The material is ASTM A403 WP321; dimensions follow ASME B16.9 · MSS SP-43. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 321 stub end?
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