Monel 400 Pipe & TubeASTM B165 UNS N04400 · Manufacturer, stockist & exporter, India
Also sold as Alloy 400 · UNS N04400 · W.Nr 2.4360 · Nicorros
Monel 400 pipe is supplied seamless to ASTM B165 and welded to ASTM B725, in ASME pipe sizes and schedules, with tube to ASTM B163 · B165. It is a nickel–copper alloy, chosen for seawater, hydrofluoric acid and marine service. Kanak Steel & Engineering Co. supplies it with EN 10204 3.1 mill certificates from Mumbai to buyers across India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on every heat
- NACE MR0175 on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Monel 400 Pipe & Tube?
Monel 400 pipe & tube is a nickel–copper alloy supplied as pipe & tube to ASTM B165 (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
- Seamless
- ASTM B165
- Welded
- ASTM B725
- Sizes
- NPS ⅛" – 24" · OD tube to order
- Schedules
- 5S · 10S · 40S · 80S · 160 · XXS
- Best at
- Seawater, hydrofluoric acid and marine service
Monel 400 Pipe & Tube Specification & Sizes
| Seamless pipe | ASTM B165 |
|---|---|
| Welded pipe | ASTM B725 |
| Tube | ASTM B163 · B165 |
| Grade | Monel 400 · UNS N04400 · W.Nr 2.4360 |
| Size & schedule | NPS ⅛" to 24" to ASME B36.19 / B36.10; OD × wall for tube |
| Length | Single random, double random, or cut lengths |
| Ends | Plain end · bevelled end (for welding) · threaded |
| Testing | Hydrostatic or eddy-current · PMI · flattening & flaring · IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
Standards on this page
Monel 400 Pipe: Seamless, Welded or Tube?
Three different specifications cover 400 tubular products. Pick the route first — it decides price, test requirements and lead time. General requirements (tolerances, hydrostatic or electric testing) come from ASTM B829 (seamless) and B775 (welded). Schedules, the −12.5% wall tolerance and the B31.3 wall formula are explained in the pipe guide.
| Route | Specification | Use it for |
|---|---|---|
| Seamless pipe | ASTM B165 | Pressure and critical service; no weld seam to inspect. |
| Welded pipe | ASTM B725 | Economical in larger diameters and thinner walls where the code allows it. |
| Tube | ASTM B163 · B165 | Heat exchangers and instruments; ordered by exact OD × wall. |
Monel 400 Pipe Wall & Weight by Schedule
For the same size, the schedule sets the wall — and the weight you pay for. Cross-sections are drawn to scale for 2" NPS (OD 60.33 mm, ASME B36.19); weights use the density of Monel 400, 8.8 g/cm³.
Other sizes: pipe schedule chart and weight calculator.
Monel 400 Pipe & Tube Chemical Composition
| Element | Weight % |
|---|---|
| Nickel (+Co) | 63.0 min |
| Copper | 28.0 – 34.0 |
| Iron | 2.5 max |
| Manganese | 2.0 max |
| Carbon | 0.3 max |
| Silicon | 0.5 max |
| Sulphur | 0.024 max |
Monel 400 Pipe & Tube Mechanical Properties
| Annealed plate | Value |
|---|---|
| Tensile strength | 480 MPa · 70 ksi |
| Yield strength 0.2% | 195 MPa · 28 ksi |
| Elongation | 35% |
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
Values follow ASTM B127 for UNS N04400. Always check against the edition named on your purchase order.
Monel 400 Pipe Weight Chart (kg/m)
Weight per metre (kg/m) = (OD − WT) × WT × 0.02765, with OD and wall thickness in mm. The factor comes from Monel 400's density of 8.8 g/cm³.
Example: 4" Sch 40S (114.30 × 6.02 mm)
(114.30 − 6.02) × 6.02 × 0.02765 = 18.02 kg/m
| NPS | OD mm | Sch 10S kg/m | Sch 40S kg/m |
|---|---|---|---|
| ½" | 21.34 | 1.12 | 1.42 |
| 1" | 33.40 | 2.35 | 2.81 |
| 2" | 60.33 | 4.41 | 6.10 |
| 3" | 88.90 | 7.24 | 12.66 |
| 4" | 114.30 | 9.38 | 18.02 |
| 6" | 168.28 | 15.50 | 31.68 |
| 8" | 219.08 | 22.38 | 47.69 |
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 & Tube 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. We PMI-test nickel alloys as standard and any grade on request.
| Element | Monel 400 | Monel K500 |
|---|---|---|
| Nickel | 63.0 min | 63.0 min |
| Copper | 28.0 – 34.0 | 27.0 – 33.0 |
| Titanium | residual | 0.35 – 0.85 |
| Iron | 2.5 max | 2.0 max |
| Manganese | 2.0 max | 1.5 max |
Monel 400 Pipe & Tube Price — What Decides It
Two quotes for "400 pipe & tube" can differ by 20% and both be fair. We quote 400 pipe & tube 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.
Standards on this page
Monel 400 Pipe & Tube 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 & Tube vs 625, 2507 and 316L
| Grade | Pipe & Tube standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Monel 400 | ASTM B165 | — | Seawater, hydrofluoric acid and marine service |
| SS 316 / 316L | ASTM A312 TP316L | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| Super Duplex 2507 | ASTM A790 | ≈ 42 | Seawater and high-chloride service where strength also matters |
| Inconel 625 | ASTM B444 | ≈ 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 & tube order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked and material is PMI-tested before processing.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked.
- 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 & Tube
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 & Tube: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Seamless or welded, and the standard
- NPS and schedule (or OD × wall for tube)
- Length — random or cut, and number of lengths
- End finish — plain, bevelled or threaded
- Certificate type and extra tests
- Delivery port, Incoterm and required date
Monel 400 pipe & tube for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiMonel 400 pipe & tube — questions buyers ask
Is Monel 400 the same as Alloy 400?
Yes. Alloy 400, UNS N04400, W.Nr 2.4360 all refer to the same material, and pipe & tube is ordered to ASTM B165 whichever name is on the enquiry.
What is the difference between Monel 400 pipe and tube?
Pipe is ordered by nominal pipe size and schedule, for carrying fluids. Tube is ordered by exact outside diameter and wall, for heat exchangers and instruments, and is held to tighter tolerances.
Seamless or welded Monel 400 pipe — which should I buy?
Seamless (ASTM B165) is the default for pressure and critical service. Welded (ASTM B725) is cheaper in larger diameters and thinner walls and is accepted where the design code allows it.
What is the wall-thickness tolerance on Monel 400 pipe?
Seamless pipe is normally allowed −12.5% on nominal wall under its general-requirements standard (ASTM B829 (seamless) and B775 (welded)). Allow for it in the pressure calculation or order on minimum wall.
Can Monel 400 pipe be welded to carbon-steel pipe?
Yes, with the right filler: a nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel. Follow a qualified WPS.
Can you supply Monel 400 pipe & tube to NACE MR0175?
Yes. Monel 400 is listed in NACE MR0175 / ISO 15156-3 for sour service within that standard's environmental limits. State NACE compliance on the order and it is confirmed on the certificate.
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