SS 904L CouplingASTM A182 · ASME B16.11 · Manufacturer, trader & exporter, India
Alloy 904L · UNS N08904
An SS 904L coupling is a short forged fitting that joins two pipes, made from SS 904L to ASTM A182 F904L. Full couplings join two pipes; half couplings are welded to a pipe or vessel as a branch connection. Socket-weld or threaded to ASME B16.11.
For the full 904L fittings range, see SS 904L pipe fittings.
- ASTM A182
- ASME B16.11
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an SS 904L Coupling?
- What it is
- A short forged fitting that joins two pipes
- Material
- ASTM A182 F904L
- Dimensions
- ASME B16.11
- Grade
- SS 904L · UNS N08904
- Best at
- Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water
SS 904L Coupling Specification
| Product | SS 904L Coupling |
|---|---|
| Material standard | ASTM A182 F904L |
| Dimensional standard | ASME B16.11 |
| Sizes | ⅛" – 4" (ASME B16.11) |
| Wall / class | Class 2000 / 3000 / 6000 / 9000 |
| Ends | Socket weld · NPT threaded |
| 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 Coupling
Full couplings join two pipes; half couplings are welded to a pipe or vessel as a branch connection. Socket-weld or threaded to ASME B16.11.
- Full and half couplings
- Reducing couplings
- Class 3000 / 6000 / 9000
More on choosing: Coupling guide.
SS 904L Coupling: Why 904L for couplings
Full couplings join two pipes; half couplings are welded to a pipe or vessel as a branch connection. Socket-weld or threaded to ASME B16.11. In SS 904L, 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 904L is picked for dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water. |
|---|---|
| Typical service | Sulphuric acid plants — Coolers, piping and tanks for dilute sulphuric acid. |
| Welding to carbon steel | ER309L (or E309L electrode) is the usual filler when joining it to carbon steel |
| Matching filler | ER385 (AWS A5.9) |
SS 904L Coupling Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel | As specified |
| Chromium | As specified |
| Molybdenum | As specified |
| Copper | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | 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 N08904.
SS 904L Coupling 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 N08904 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 904L grade page.
Other SS 904L pipe fittings
SS 904L Coupling — questions buyers ask
What is a half coupling used for?
It is welded onto a pipe or vessel to create a small threaded or socket-weld branch.
Can SS 904L couplings be welded to carbon steel?
Yes — ER309L (or E309L electrode) is the usual filler when joining it to carbon steel.
Which standard covers SS 904L couplings?
The material is ASTM A182 F904L; dimensions follow ASME B16.11. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 904L coupling?
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