SS 304L Stub EndASTM A403 · ASME B16.9 · Manufacturer, trader & exporter, India
AISI 304L · UNS S30403
An SS 304L stub end is a short pipe length with a flared lap that works with a lap joint flange, made from SS 304L to ASTM A403 WP304L. 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 304L Stub End?
- What it is
- A short pipe length with a flared lap that works with a lap joint flange
- Material
- ASTM A403 WP304L
- Dimensions
- ASME B16.9 · MSS SP-43
- Grade
- SS 304L · UNS S30403
- Best at
- Welded tanks, piping and vessels in general corrosive service
SS 304L Stub End Specification
| Product | SS 304L Stub End |
|---|---|
| Material standard | ASTM A403 WP304L |
| 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 (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 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
More on choosing: Stub end guide.
SS 304L Stub End: Why 304L for stub ends
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. In SS 304L, 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 304L is picked for welded tanks, piping and vessels in general corrosive service. |
|---|---|
| Typical service | Process piping — Welded lines in chemical and pharma plants. |
| Welding to carbon steel | ER309L (or E309L electrode) is the usual filler when joining it to carbon steel |
| Matching filler | ER308L (AWS A5.9) |
SS 304L Stub End Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | As specified |
| Phosphorus | As specified |
| Sulphur | 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 S30403.
SS 304L Stub End 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 S30403 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 304L grade page.
Other SS 304L pipe fittings
SS 304L 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.
Can SS 304L stub ends be welded to carbon steel?
Yes — ER309L (or E309L electrode) is the usual filler when joining it to carbon steel.
Which standard covers SS 304L stub ends?
The material is ASTM A403 WP304L; 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 304L 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 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