Monel 400 Pipe FittingsASTM B366 WPNC · Manufacturer, trader & exporter, India
Also sold as Alloy 400 · UNS N04400 · W.Nr 2.4360 · Nicorros
Monel 400 pipe fittings are made to ASTM B366 WPNC for buttweld fittings and ASTM B564 for forged socket-weld and threaded fittings, with dimensions to ASME B16.9 and B16.11. It is a nickel–copper alloy, chosen for seawater, hydrofluoric acid and marine service. Kanak Steel & Engineering Co. manufactures, trades and exports it from Mumbai; EN 10204 3.1 or 3.2 certificates are available on request / as specified in the PO. Markets we have supplied to include Oman, UAE, Saudi Arabia, Brazil, Argentina, Spain and Chile (India is the home market).
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on request
- NACE MR0175 on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Monel 400 Pipe Fittings?
Monel 400 pipe fittings is a nickel–copper alloy supplied as pipe fittings to ASTM B366 WPNC (UNS N04400). Buyers specify it for seawater, hydrofluoric acid and marine service. It is also sold as Alloy 400, UNS N04400, W.Nr 2.4360.
- What it is
- Nickel–copper alloy
- Buttweld
- ASTM B366 WPNC
- Forged
- ASTM B564
- Dimensions
- ASME B16.9 · B16.11 · MSS SP-43
- Sizes
- Buttweld ½" – 48" · forged ⅛" – 4"
- Best at
- Seawater, hydrofluoric acid and marine service
Monel 400 Pipe Fittings Specification & Sizes
| Buttweld fittings | ASTM B366 WPNC — dimensions to ASME B16.9, MSS SP-43 |
|---|---|
| Forged fittings | ASTM B564 — dimensions to ASME B16.11 |
| Short-radius elbows | ASME B16.9 (formerly B16.28) |
| Buttweld sizes | NPS ½" to 48", schedule to match the pipe |
| Forged classes | Socket weld 3000 / 6000 / 9000 · threaded 2000 / 3000 / 6000 |
| Types | Elbow · Tee · Reducer · Cap · Stub end · Cross · Bend · Lateral · Coupling · Union · Nipple · Plug |
| Testing | PMI · dimensional · radiography of welded fittings · IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
Choosing Monel 400 Fittings: Elbow Radius, Schedule & Class
State seamless or welded, and the non-destructive examination you need on welds.
Radius (LR, SR, 3D), the schedule-to-class map and the 1.5 mm socket-weld gap are explained in the fittings guide. For 400, buttweld fittings are ASTM B366 WPNC and forged fittings ASTM B564.
Monel 400 Pipe Fittings Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel (+Co) | As specified |
| Copper | As specified |
| Iron | As specified |
| Manganese | As specified |
| Carbon | As specified |
| Silicon | 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 B127 for UNS N04400.
Monel 400 Pipe Fittings Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | 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 B127 for UNS N04400 — Annealed plate.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8.8 g/cm³ |
| Melting range | 1300 – 1350 °C |
| Magnetic | Slightly magnetic at room temperature |
Monel 400 Equivalent Grades
Monel 400 buttweld fitting dimensions — ASME B16.9
Centre-to-end and end-to-end dimensions are the same for every alloy; the wall thickness follows the pipe schedule. Values in mm.
| NPS | OD | 90° LR elbow A | 45° elbow B | Tee C | Reducer H | Cap E |
|---|---|---|---|---|---|---|
| ½" | 21.3 | 38 | 16 | 25 | — | 25 |
| 1" | 33.4 | 38 | 22 | 38 | 51 | 38 |
| 1½" | 48.3 | 57 | 29 | 57 | 64 | 38 |
| 2" | 60.3 | 76 | 35 | 64 | 76 | 38 |
| 3" | 88.9 | 114 | 51 | 86 | 89 | 51 |
| 4" | 114.3 | 152 | 64 | 105 | 102 | 64 |
| 6" | 168.3 | 229 | 95 | 143 | 140 | 89 |
| 8" | 219.1 | 305 | 127 | 178 | 152 | 102 |
| 10" | 273.1 | 381 | 159 | 216 | 178 | 127 |
| 12" | 323.9 | 457 | 190 | 254 | 203 | 152 |
Full chart to 24": ASME B16.9 fitting dimensions.
Six-digit Harmonized System heading (nickel alloy, chapter 75). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify Monel 400 Pipe Fittings with PMI
Positive material identification with a handheld XRF gun confirms the alloy on the piece itself, in seconds, before it is cut or welded. Monel 400 is most often mixed up with Monel K500 — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen; those come from the mill certificate or optical emission (OES) testing. PMI can be arranged on request — state it on your enquiry.
Under technical review for TDS.
| Element | Monel 400 | Monel K500 |
|---|---|---|
| Nickel | As specified | As specified |
| Copper | As specified | As specified |
| Titanium | — | As specified |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
Monel 400 Pipe Fittings Price — What Decides It
Two quotes for "400 pipe fittings" can differ by 20% and both be fair. We quote 400 pipe fittings per kg for full sizes and per piece for cut sizes. These six things move the price per kg, so you can compare offers like for like.
Monel 400 pipe fittings by type
Monel 400 Pipe Fittings Applications
Monel 400 is specified when the cheaper grade will not survive the service but a higher alloy would be more than the job needs. These are the jobs our buyers use it for.
Monel 400 Pipe Fittings vs 625, 2507 and 316L
| Grade | Pipe Fittings standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Monel 400 | ASTM B366 WPNC | — | Seawater, hydrofluoric acid and marine service |
| SS 316 / 316L | ASTM A403 WP316L | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| Super Duplex 2507 | ASTM A815 WPS32750 | ≈ 42 | Seawater and high-chloride service where strength also matters |
| Inconel 625 | ASTM B366 WPNCMC | ≈ 51 | Seawater, high strength and high temperature in one alloy |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Monel 400 Corrosion Resistance — Element by Element
Each alloying addition has a job. Knowing which one protects against your medium is the quickest way to judge whether 400 fits.
Very low corrosion rates in flowing seawater and brackish water.
One of the few alloys that handles hydrofluoric acid in all concentrations (air-free).
Resists caustic alkalis and chloride stress-corrosion cracking.
Avoid nitric acid, aerated ammonia and oxidising salts.
How your 400 pipe fittings order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked against your order; PMI can be arranged depending on product and requirements, as specified in the PO.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked as specified in the PO.
- 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
- 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.
Standards on this page
Welding & Fabricating Monel 400 Pipe Fittings
Monel 400 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ERNiCu-7 (AWS A5.14) |
|---|---|
| Over-alloyed filler | ENiCu-7 electrode |
| Preheat | Not required; keep interpass temperature low |
| Cutting | Thermal or abrasive cutting; grind off heat-tinted edges before welding |
Follow your approved WPS; this is general guidance. See also 400 fittings and 400 flanges for the matching pipe-system parts.
How to Order Monel 400 Pipe Fittings: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Fitting type, size and schedule / class
- Buttweld, socket weld or threaded
- Seamless or welded (buttweld fittings)
- Material standard and grade marking
- Certificate type and extra tests
- Delivery port, Incoterm and required date
Monel 400 pipe fittings — questions buyers ask
Is Monel 400 the same as Alloy 400?
Alloy 400, UNS N04400, W.Nr 2.4360 are names used for Monel 400 (W.Nr / EN numbers and older UNS variants are the closest designations; their limits can differ slightly, so specify the UNS number and ASTM grade on the order), and pipe fittings is ordered to ASTM B366 WPNC whichever name is on the enquiry.
Which standard covers Monel 400 buttweld fittings?
ASTM B366 WPNC is the material specification; dimensions follow ASME B16.9 (and MSS SP-43 for light-wall fittings). Forged socket-weld and threaded fittings are made from ASTM B564 material to ASME B16.11.
What is the difference between Monel 400 WP-S and WP-W fittings?
Seamless fittings are made from seamless pipe or bar; welded fittings are formed from plate or welded pipe. State which you need and the weld examination required.
Can Monel 400 fittings be welded to carbon steel?
Yes — a nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel.
Can Monel 400 pipe fittings be supplied to NACE MR0175?
Monel 400 (UNS N04400) can be supplied for sour service when the PO specifies NACE MR0175 / ISO 15156; acceptability depends on the material condition, hardness and the environmental limits in that standard, which the purchaser must confirm for the application.
Monel 400 or SS 316 / 316L — which should I choose?
Monel 400 is chosen for seawater, hydrofluoric acid and marine service. SS 316 / 316L is the step up when you need more pitting resistance or strength. See the comparison table on this page, or ask us with your process conditions.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026