Nickel alloy · JIS NW4400 · UNS N04400 · W.Nr. 2.4360
NW4400 Forgings Nickel-copper alloy rolled rings, flanges, bars, discs and shafts, open-die forged to ASTM B564 / ASME SB-564.
NW4400 is the Japanese Industrial Standard (JIS) designation for the nickel-copper alloy known internationally as UNS N04400, Monel 400, Alloy 400 and Werkstoff 2.4360 (NiCu30Fe). It contains a minimum of 63% nickel and 28–34% copper, and it is a solid-solution alloy that cannot be hardened by heat treatment.
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, forges NW4400 into seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets to ASTM B564 / ASME SB-564, supplied annealed, ultrasonically tested and certified to EN 10204 3.1 or 3.2. For a quotation, contact sales@steelforgepieces.com or +86 189 2135 9659.
If a drawing or purchase order reaches you marked NW4400, it is the same material as Monel 400. No substitution or engineering deviation is involved. The section below explains where the designation comes from, so you can confirm it against your specification in one step.
Why the grade is called NW4400
JIS H4551 / H4552 / H4553
Naming rule: JIS wrought nickel-alloy grades keep the last four digits of the UNS number and replace the prefix with NW. UNS N04400 becomes NW4400, UNS N06625 becomes NW6625, and UNS N10276 becomes NW0276. NW4400 and N04400 are one alloy under two naming systems.
01 / Summary
NW4400 at a glance
- Grade
- NW4400 (also written NW 4400, JIS NW4400)
- UNS number
- N04400
- Common name
- Monel® 400, Alloy 400, Nickel 400
- Werkstoff / DIN
- 2.4360 / NiCu30Fe (DIN 17744)
- Alloy family
- Nickel-copper, solid-solution, non-hardenable
- Nominal chemistry
- Ni ≥63% · Cu 28–34% · Fe ≤2.5%
- Forging standard
- ASTM B564 / ASME SB-564
- Delivery condition
- Annealed (hot-finished or hot-finished + annealed)
- Tensile, min
- 480 MPa (70 ksi)
- Yield 0.2%, min
- 195 MPa (28 ksi)
- Elongation, min
- 35%
- Density
- 8.80 g/cm³ (0.318 lb/in³)
- Melting range
- 1300–1350 °C (2370–2460 °F)
- Service ceiling
- ≈538 °C (1000 °F) in air
- Best known for
- Hydrofluoric acid and seawater service
- Certification
- EN 10204 3.1 standard, 3.2 on request
- Forged by
- Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China
02 / Material overview
What NW4400 is, and when to specify it
NW4400 is a single-phase nickel-copper alloy of roughly 66% nickel and 31% copper. Its strength comes from solid-solution hardening and from cold work. There is no precipitation-hardening mechanism, so the alloy is annealed or work-hardened, never aged.
The alloy sits between stainless steel and the nickel-chromium-molybdenum grades in both cost and capability. Its copper content gives it strong resistance in reducing environments, hydrofluoric acid above all. Its high nickel content gives near-immunity to chloride stress-corrosion cracking, which is the failure mode that most often takes out 304 and 316 stainless in warm chloride service.
Oxidising conditions are the limitation. Copper becomes a liability wherever the environment is oxidising, and nitric acid, ferric or cupric chloride, chromic acid and oxidising salts all attack NW4400 quickly. Selection therefore depends on the chemistry of the process stream more than on the strength required.
Specify NW4400 when
- The stream contains hydrofluoric acid. Alloy 400 is the reference material for HF alkylation units at all concentrations and up to about 150 °C.
- The part runs in seawater or brine. It resists flowing seawater, cavitation and erosion far better than copper alloys, and does not crack in chlorides.
- The acid is reducing. Dilute sulfuric, hydrochloric below about 20% at room temperature, and hydrofluoric.
- Caustic service. Sodium hydroxide at all concentrations and temperatures, including molten, where it out-performs nickel-chromium grades.
- Cryogenic duty. The face-centred-cubic structure keeps toughness down to −196 °C with no ductile-to-brittle transition.
Choose something else when
- The environment is oxidising. Nitric acid, ferric chloride, cupric chloride, chromic acid, wet chlorine, hypochlorite. Use Hastelloy C-276 or Alloy 625.
- Sulfur is present above 425 °C. Sulfur-bearing gases embrittle the alloy at temperature.
- You need higher strength. Monel K-500 (UNS N05500) is the age-hardenable version, roughly twice the yield strength, same corrosion behaviour.
- Mercury is present. NW4400 is subject to liquid-metal embrittlement by mercury.
- Ammonia is moist and aerated. Stress-corrosion cracking can occur; stress relief helps, but a different alloy is safer.
03 / Designation
NW4400 vs Monel 400 vs Alloy 400: are they the same?
Yes. NW4400, Monel 400, Alloy 400, UNS N04400, W.Nr. 2.4360 and NiCu30Fe all describe one material. The Japanese, German, trade and generic naming systems all point at the same chemistry.
This matters on the purchase order, because the names carry different legal weight. Monel® is a registered trademark of Special Metals Corporation. Material made by that company and sold under that name is theirs. Material produced independently, including everything we forge, is correctly described as UNS N04400 to ASTM B564, which is the same generic chemistry, specified without reference to anyone's trademark.
| Name | Naming system | Use it when |
|---|---|---|
| NW4400 | JIS (Japan), H4551 / H4552 / H4553 | The drawing or specification originates in Japan, or from a Japanese licensor |
| N04400 | UNS (USA / international) | Always. The unambiguous designation to write on a purchase order |
| Alloy 400 | Generic industry name | Trademark-neutral commercial description |
| Monel® 400 | Trade name, Special Metals Corp. | Only when the trademark holder's material is genuinely required |
| 2.4360 | Werkstoff Nr. (Germany) | European drawings, DIN / EN specifications |
| NiCu30Fe | DIN 17744 chemical name | German and EN material specifications |
The JIS NW series, decoded
Because JIS keeps the last four digits of the UNS number, any NW designation can be read straight off against a UNS cross-reference:
| JIS | UNS | Common name |
|---|---|---|
| NW2200 | N02200 | Nickel 200 (commercially pure nickel) |
| NW2201 | N02201 | Nickel 201 (low-carbon nickel) |
| NW4400 | N04400 | Monel 400 / Alloy 400 (this page) |
| NW6600 | N06600 | Inconel 600 |
| NW6625 | N06625 | Inconel 625 |
| NW0276 | N10276 | Hastelloy C-276 |
| NW8800 | N08800 | Incoloy 800 |
| NW8825 | N08825 | Incoloy 825 |
Note the pattern in NW0276: the UNS number N10276 has five digits, so the leading 1 is dropped and only 0276 is retained. Where a code registration or design approval is involved, order to the UNS number and confirm the equivalence against the mill certificate.
04 / Chemistry
Chemical composition of NW4400 (UNS N04400)
NW4400 is specified as minimum 63.0% nickel, 28.0–34.0% copper, maximum 2.5% iron, maximum 2.0% manganese, maximum 0.3% carbon, maximum 0.5% silicon and maximum 0.024% sulfur, by weight.
Composition limits below are those of ASTM B564 / ASME SB-564 for UNS N04400, which align with DIN 17744 for 2.4360 (NiCu30Fe). Note that nickel is specified as a minimum and the balance is made up by copper. Unlike most alloys, there is no single "balance" element.
| Element | Min % | Max % | Role in the alloy |
|---|---|---|---|
| Nickel (Ni) | 63.0 | - | Immunity to chloride stress-corrosion cracking; caustic and HF resistance |
| Copper (Cu) | 28.0 | 34.0 | Resistance in reducing acids, seawater and brine; biofouling resistance |
| Iron (Fe) | - | 2.5 | Residual from melting; assists resistance in flowing seawater |
| Manganese (Mn) | - | 2.0 | Deoxidiser; combines with sulfur to protect hot workability |
| Carbon (C) | - | 0.30 | Residual. Kept low in practice for weldability |
| Silicon (Si) | - | 0.50 | Deoxidiser |
| Sulfur (S) | - | 0.024 | Kept low for hot workability and toughness |
DIN 17744 states sulfur as 0.025% maximum; ASTM B564 and ASTM B164 state 0.024% maximum. Order to whichever standard your design registration cites. Every heat we forge is supplied with a ladle analysis on the mill certificate; product analysis on the finished forging can be added on request.
If the part is a high-volume machined component such as a valve stem or fastener, ask about Monel R-405 (UNS N04405). It is the same base chemistry with sulfur raised to 0.025–0.060% to break up chips. Corrosion behaviour is close to identical, but weldability is poor, so do not specify R-405 for a part that will be welded.
05 / Mechanical properties
Mechanical properties of NW4400 forgings
Specified minimums to ASTM B564 / ASME SB-564, annealed
These are the values a mill certificate must meet. They are minimums, not typical values, and they match the DIN 17744 minima for 2.4360 in the annealed condition.
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength, min | 480 MPa | 70 ksi |
| Yield strength 0.2% offset, min | 195 MPa | 28 ksi |
| Elongation in 50 mm (2 in), min | 35% | 35% |
| Reduction of area, typical | ≥50% | ≥50% |
Typical as-delivered values
Annealed NW4400 forgings normally test comfortably above the specified minimums. The values below are representative of our production and vary with section size, reduction ratio and cooling rate.
| Property | Typical range (metric) | Typical range (imperial) |
|---|---|---|
| Tensile strength | 517–620 MPa | 75–90 ksi |
| Yield strength 0.2% | 205–345 MPa | 30–50 ksi |
| Elongation | 40–55% | 40–55% |
| Hardness | 110–150 HB | 65–80 HRB |
| Impact, Charpy V at −196 °C | no transition | no transition |
Typical values are for design screening only. The mill test certificate issued with each forging governs acceptance. Where a minimum yield above 345 MPa is required, the alloy to specify is Monel K-500 (UNS N05500), not a cold-worked NW4400 forging.
NW4400 is not age-hardenable. It is a solid-solution alloy, and a solution-treat-and-age cycle will not raise its strength. It will only anneal the material. Drawings that call for "solution treatment plus ageing" on N04400 have almost always been copied from a K-500 or 17-4PH specification. If your drawing says this, send it to us before the order is placed and we will flag it in writing.
06 / Physical properties
Physical properties of NW4400
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.80 g/cm³ | 0.318 lb/in³ |
| Melting range | 1300–1350 °C | 2370–2460 °F |
| Modulus of elasticity | 179 GPa | 26 × 10⁶ psi |
| Specific heat | 427 J/kg·K | 0.102 Btu/lb·°F |
| Thermal conductivity, 20 °C | 21.8 W/m·K | 151 Btu·in/ft²·h·°F |
| Mean expansion, 20–100 °C | 13.9 µm/m·K | 7.7 × 10⁻⁶ in/in·°F |
| Electrical resistivity | 0.547 µΩ·m | 329 Ω·circ mil/ft |
| Curie temperature | ≈20–50 °C | ≈70–120 °F |
NW4400 has a Curie temperature close to room temperature, and it varies with the iron and copper content of the individual heat. One heat can be weakly magnetic at 20 °C while another is not. If your specification requires non-magnetic material, NW4400 is the wrong choice. If a permeability limit is written into the order, state it explicitly so we can test each heat against it before despatch.
The density of 8.80 g/cm³ matters at the quotation stage. NW4400 is about 12% heavier than carbon steel and 10% heavier than 316 stainless, so a forging weight calculated from a steel drawing will be understated. We recalculate net and gross weight from your drawing as part of every quotation.
07 / Corrosion performance
Corrosion resistance of NW4400: where it works and where it fails
NW4400 resists reducing environments and is attacked by oxidising ones. It performs well in hydrofluoric acid, seawater, brine, caustic soda and dilute sulfuric and hydrochloric acid. Nitric acid, ferric chloride, cupric chloride, wet chlorine and hypochlorites corrode it rapidly.
| Environment | Rating | Engineering note |
|---|---|---|
| Hydrofluoric acid | Excellent | The reference material for HF service at all concentrations to about 150 °C. Watch for SCC in aerated HF vapour on highly stressed parts; stress relieve. |
| Flowing seawater | Excellent | Resists erosion, cavitation and high-velocity impingement. Standard for pump and propeller shafts. |
| Stagnant seawater | Fair | Susceptible to pitting and crevice attack under deposits or gaskets. Design out crevices, or keep the flow moving. |
| Sodium hydroxide | Excellent | All concentrations and temperatures, including molten caustic. Better than nickel-chromium grades here. |
| Hydrochloric acid | Good | Up to about 20% at room temperature under reducing (air-free) conditions. Aeration or oxidising salts destroy the performance. |
| Sulfuric acid | Good | Below about 85% at moderate temperature, air-free. Not for aerated or oxidising conditions. |
| Chloride SCC | Immune in practice | The high nickel content makes it effectively immune, unlike 304 and 316 stainless. |
| Nitric acid | Poor | Oxidising. Rapid attack at any concentration. Specify 304L or Alloy 625. |
| Ferric / cupric chloride | Poor | Strongly oxidising chlorides cause rapid pitting. Specify Hastelloy C-276. |
| Wet chlorine, hypochlorite | Poor | Not suitable. Specify Hastelloy C-276 or Alloy 59. |
| Moist aerated ammonia | Poor | Stress-corrosion cracking risk above about 0.2% moisture. Stress relief reduces but does not remove the risk. |
| Mercury | Not permitted | Liquid-metal embrittlement. Do not use in mercury-bearing service. |
| Sulfur gases >425 °C | Not permitted | Sulfur embrittles the alloy at temperature. Hard limit for design. |
Ratings are for guidance in material screening. Corrosion behaviour depends on concentration, temperature, aeration, velocity, contaminants and stress state, and no table replaces a coupon test or a corrosion engineer's review of the specific service.
Sour service
Nickel-copper alloy 400 appears in ISO 15156-3 / NACE MR0175 for certain sour-service applications, with limits on hydrogen sulfide partial pressure, chloride content, temperature and hardness. The permitted envelope is narrow and depends on the component type. If your order is for sour service, cite the applicable table from ISO 15156-3 on the purchase order and we will certify the forging against it, including the maximum hardness requirement.
08 / Forging & heat treatment
Forging practice and heat treatment for NW4400
NW4400 is forged from 1150–1200 °C and finished above 870 °C, then annealed at 760–870 °C. It is never solution treated and aged, because it contains no precipitation-hardening elements.
| Operation | Temperature | Practice |
|---|---|---|
| Forging, start | 1150–1200 °C 2100–2190 °F | Do not exceed 1200 °C. Overheating in a sulfur-bearing furnace atmosphere causes hot shortness. |
| Forging, finish | ≥870 °C ≥1600 °F | Light finishing below this raises strength through residual cold work and produces a non-uniform grain. |
| Annealing | 760–870 °C 1400–1600 °F | Hold to section, then cool rapidly. This is the standard delivery condition for forgings. |
| Stress relief (cold worked) | 275–300 °C 530–570 °F | 1–3 hours. Used to reduce residual stress without softening a cold-worked part. |
| Age hardening | Not applicable | NW4400 contains no aluminium or titanium and cannot be precipitation hardened. Use Monel K-500 if ageing is required. |
Sulfur damages this alloy in the furnace as well as in service. Heating must be done in a low-sulfur atmosphere: sulfur-free fuel, no oil residue on the stock, and no contact with sulfur-bearing refractories or marking materials. Sulfur pick-up during heating causes intergranular hot cracking that will not show up until after forging.
Machining and welding
NW4400 work-hardens rapidly. Machine with positive rake, sharp tooling, heavy feeds and low speeds, and never allow the tool to dwell. A rubbing tool glazes the surface, and the next pass then cuts hardened material. In the annealed condition the alloy is gummy; many shops prefer to machine it slightly cold-worked.
It welds readily by GTAW, GMAW and SMAW. The usual filler metals are ERNiCu-7 (UNS N04060) for GTAW and GMAW, and ENiCu-7 (UNS W84190) for SMAW. Post-weld heat treatment is not normally required for the alloy itself, though stress relief should be specified for HF vapour or moist-ammonia service.
09 / Cross-reference
NW4400 equivalent designations
| System | Designation |
|---|---|
| JIS (Japan) | NW4400 |
| UNS (USA / international) | N04400 |
| Werkstoff Nr. (Germany) | 2.4360 |
| DIN / EN chemical name | NiCu30Fe (DIN 17744) |
| BS (UK) | NA13 (BS 3072–3076) |
| AFNOR (France) | NU30 (nearest) |
| GB/T (China) | NCu30 / NCu28-2.5-1.5 |
| GOST (Russia) | МНЖМц 28-2.5-1.5 (nearest) |
| ISO | NiCu30Fe |
| AMS (aerospace) | AMS 4675 (bar), AMS 4544 (plate, sheet) |
| Trade names | Monel® 400, Nicorros® 400, Ferrochronin® 400 |
Designations marked "nearest" are close but not identical matches, and their composition windows differ slightly at the margins. Where a code case, PED registration or design approval is involved, order to the UNS number and confirm equivalence against the mill certificate. Monel is a registered trademark of Special Metals Corporation; Jiangyin Jiangnan Metal Co., Ltd. is not affiliated with the trademark holder, and the name is used here only to identify the alloy specification.
10 / Standards
Applicable standards by product form
| Product form | ASTM | ASME |
|---|---|---|
| Forgings (our core product) | B564 | SB-564 |
| Rod, bar and wire | B164 | SB-164 |
| Plate, sheet and strip | B127 | SB-127 |
| Seamless pipe and tube | B165, B163 | SB-165, SB-163 |
| Welded pipe | B725 | SB-725 |
| Welded tube | B730 | SB-730 |
| Fittings | B366 | SB-366 |
| Flanges (dimensional) | ASME B16.5, B16.47, or customer drawing | |
| Sour service | ISO 15156-3 / NACE MR0175, within the stated limits | |
| Certification | EN 10204 3.1 standard; 3.2 third-party witnessed on request | |
For pressure-retaining design, UNS N04400 is code-listed in the ASME Boiler and Pressure Vessel Code, Section II Part D, with allowable stresses tabulated for elevated temperature. Confirm the tabulated ceiling against your design temperature before finalising the material selection, and note that the practical service limit is set by strength loss well before the oxidation limit is reached.
11 / Alloy selection
NW4400 compared with the alternatives
Four grades come up repeatedly when NW4400 is on the table. The choice is usually decided by one question: is the environment reducing or oxidising?
| Criterion | NW4400 / N04400 | Monel K-500 / N05500 | 316L / S31603 | Alloy 625 / N06625 |
|---|---|---|---|---|
| Type | Ni-Cu, solid solution | Ni-Cu, age hardenable | Austenitic stainless | Ni-Cr-Mo, solid solution |
| Yield, min | 195 MPa | 690 MPa | 170 MPa | 414 MPa |
| Hydrofluoric acid | Excellent | Excellent | Poor | Fair |
| Seawater, flowing | Excellent | Excellent | Fair | Excellent |
| Oxidising acids | Poor | Poor | Good | Excellent |
| Chloride SCC | Immune | Immune | Susceptible | Immune |
| Max service, air | ≈538 °C | ≈480 °C | ≈870 °C | ≈980 °C |
| Relative cost | Medium | High | Low | High |
| Choose it when | HF, seawater, caustic, reducing acids | Same environments, but you need strength or a non-galling shaft | Mild service, cost governs, no chlorides | Oxidising and mixed-acid service, high temperature |
Use NW4400 for reducing acids, hydrofluoric acid and seawater. Use Monel K-500 where the same environment needs about double the yield strength. Use Alloy 625 or Hastelloy C-276 where the environment is oxidising.
12 / Product range
NW4400 forgings we produce
Jiangyin Jiangnan Metal Co., Ltd. produces NW4400 seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings, tube sheets, valve components and custom open-die shapes, all forged to the customer's drawing.
Every item below is open-die work. There is no fixed catalogue, no die cost and no minimum order quantity by piece, so one-off and prototype items are economic to make.
Size and weight capability
| Product form | Dimensional range | Unit weight |
|---|---|---|
| Seamless rolled rings | OD 200–3,000 mm, height to 800 mm | 20–8,000 kg |
| Round bars | Ø80–800 mm, length to 6,000 mm | 20–6,000 kg |
| Discs and tube sheets | Ø200–2,500 mm, thickness to 600 mm | 30–10,000 kg |
| Shafts, sleeves, blocks | to 6,000 mm long | to 10,000 kg |
Machining allowance is normally 6–20 mm per surface depending on section size, unless your drawing states otherwise. We also supply finish-machined parts to print. Because NW4400 is 12% denser than steel, send the drawing rather than a target weight and we will calculate net and gross mass for you.
13 / Manufacturing route
How we make NW4400 forgings
- MeltingNW4400 stock is melted by EAF + AOD/VOD, with ESR remelting available when the specification or the service calls for improved cleanliness and reduced segregation.
- Ingot and billet verificationHeat chemistry is checked by spectrometer against the ASTM B564 limits for nickel minimum, copper window, iron and sulfur maxima before any material is heated.
- Heating in a low-sulfur atmosphereStock is cleaned of oil and marking residue and heated to 1150–1200 °C in a sulfur-free atmosphere, because sulfur pick-up at temperature causes intergranular hot cracking.
- Open-die forgingForged on hydraulic presses with a controlled reduction ratio to close porosity and develop a wrought grain flow that follows the part contour. Forging is finished above 870 °C. Rings are rolled seamless.
- AnnealingHeld at 760–870 °C to section thickness, then cooled rapidly. This is the standard delivery condition. NW4400 is never age hardened.
- Rough or finish machiningTurned, bored, drilled and faced to your drawing, with the agreed machining allowance or to final dimensions.
- Non-destructive testingUltrasonic examination to ASTM A388, EN 10228-3 or SEP 1921 class as nominated, plus liquid penetrant and dimensional inspection where required.
- Certification and despatchEN 10204 3.1 mill certificate as standard, 3.2 with third-party witness on request. Hard stamped, preserved and packed for sea or air freight.
14 / Applications
Where NW4400 forgings are used
| Industry | Components forged in NW4400 |
|---|---|
| Refining, HF alkylation | Valve bodies, bonnets and seat rings, forged flanges, nozzle forgings, exchanger tube sheets, pump casings and acid-service piping components. NW4400 is the standard material of construction for these units. |
| Marine and naval | Propeller and pump shafts, seawater valve bodies, sea chest and strainer components, fasteners, sleeves and bushings for seawater lift pumps. |
| Offshore oil and gas | Wellhead and Christmas tree components, subsea valve parts, sour-service forgings within ISO 15156-3 limits, riser and manifold hardware. |
| Chemical processing | Reactor internals, agitator shafts, forged nozzles, blind covers and heat exchanger tube sheets for hydrochloric, sulfuric and hydrofluoric service. |
| Chlor-alkali and caustic | Caustic evaporator forgings, valve components and pump parts for sodium hydroxide at all concentrations. |
| Desalination and brine | Evaporator and brine heater components, forged tube sheets, pump shafts and impeller hubs for salt and food-grade brine plants. |
| Pumps and valves | Plunger and chemical pump shafts, seat rings, stems, gate and plug blanks, check and globe valve bodies. |
| Cryogenic | Forged flanges and valve bodies for service to −196 °C, where the alloy shows no ductile-to-brittle transition. |
15 / Quality
Testing, inspection and certification
- Chemical analysis. Spectrometric heat analysis and, on request, product analysis on the finished forging.
- Mechanical testing. Room-temperature tensile, yield and elongation per ASTM B564; elevated and cryogenic temperature testing and Charpy impact to your specification.
- Hardness. Brinell or Rockwell as specified, including the maximum hardness limit required for sour service under ISO 15156-3.
- Grain size. Determined per ASTM E112 where the order calls for it.
- Ultrasonic testing. ASTM A388, EN 10228-3, SEP 1921 class C/D/E or customer class.
- Surface NDT. Liquid penetrant examination per ASTM E165 / ASME Section V Article 6.
- Magnetic permeability. Measured per heat when a permeability limit is written into the order. This is necessary for an alloy whose Curie point is near room temperature.
- Certification. EN 10204 3.1 as standard; EN 10204 3.2 witnessed by TÜV, BV, LR, SGS or DNV on request. Full heat traceability and hard stamping.
16 / Questions
Frequently asked questions about NW4400
What is NW4400?
NW4400 is the Japanese Industrial Standard (JIS) designation for a nickel-copper alloy containing a minimum of 63% nickel and 28–34% copper. It is the same material as UNS N04400, Monel 400, Alloy 400 and Werkstoff 2.4360 (NiCu30Fe). The JIS designation is formed by taking the last four digits of the UNS number and adding the prefix NW, so N04400 becomes NW4400. It is used where reducing acids, hydrofluoric acid, seawater or caustic soda would attack stainless steel.
Is NW4400 the same as Monel 400?
Yes. NW4400, Monel 400, Alloy 400, UNS N04400 and W.Nr. 2.4360 all describe one alloy with the same chemistry and the same properties. Monel® is a registered trademark of Special Metals Corporation, so material produced by other manufacturers is correctly described as UNS N04400 to ASTM B564 rather than by the trade name. When ordering, write UNS N04400 and the governing standard on the purchase order, because that description is unambiguous and trademark-neutral.
What is the equivalent of NW4400 in other standards?
NW4400 is equivalent to UNS N04400 (USA), Werkstoff 2.4360 and NiCu30Fe under DIN 17744 (Germany), NA13 under BS 3072–3076 (UK), NCu30 or NCu28-2.5-1.5 under GB/T (China), and NU30 under AFNOR (France, nearest match). In aerospace it appears as AMS 4675 for bar and AMS 4544 for plate and sheet. Where a code registration is involved, order to the UNS number and confirm the equivalence against the mill certificate rather than relying on a cross-reference table.
Can NW4400 be hardened by heat treatment?
No. NW4400 is a solid-solution alloy containing no aluminium or titanium, so it has no precipitation-hardening mechanism. It can only be strengthened by cold work. A solution-treat-and-age cycle will not raise its strength; it will simply anneal the material. Drawings calling for ageing on N04400 have usually been copied from a Monel K-500 or 17-4PH specification. If higher strength is required in the same corrosive environment, specify Monel K-500 (UNS N05500), which is age hardenable and reaches roughly 690 MPa minimum yield strength.
What is the correct heat treatment for NW4400 forgings?
Anneal at 760–870 °C (1400–1600 °F), held to section thickness and then cooled rapidly. That is the standard delivery condition for forgings. Forging itself is carried out from 1150–1200 °C and finished above 870 °C. For cold-worked parts, a stress relief at 275–300 °C for one to three hours reduces residual stress without softening the material. No ageing treatment is applied to this grade at any stage.
Is NW4400 magnetic?
It can be. The Curie temperature of NW4400 sits close to room temperature, roughly 20–50 °C, and its precise value shifts with the iron and copper content of each individual heat. One heat can be weakly magnetic at 20 °C while the next is not. If your application requires reliably non-magnetic material, this is the wrong alloy. If a magnetic permeability limit applies, state it on the purchase order so each heat can be measured against it before despatch.
Where does NW4400 fail?
In oxidising environments. Nitric acid, ferric chloride, cupric chloride, chromic acid, wet chlorine and hypochlorites attack it rapidly, and Hastelloy C-276 or Alloy 625 should be specified instead. It must not be used in mercury-bearing service because of liquid-metal embrittlement, or above 425 °C in sulfur-bearing gases. Stress-corrosion cracking can occur in moist aerated ammonia and in aerated hydrofluoric acid vapour on highly stressed parts, where stress relief reduces but does not eliminate the risk. In stagnant seawater it is subject to crevice and pitting attack under deposits, although it performs excellently in flowing seawater.
What is the maximum service temperature of NW4400?
About 538 °C (1000 °F) in air for continuous service, limited by loss of strength rather than by oxidation. In sulfur-bearing atmospheres the limit drops to 425 °C (800 °F), because sulfur embrittles the alloy at temperature. Treat that as a hard design limit. At the other end of the range the alloy has no ductile-to-brittle transition and stays tough down to −196 °C, which is why it is used for cryogenic valve and flange forgings.
What sizes of NW4400 forgings can you supply?
Seamless rolled rings from 200 to 3,000 mm outside diameter, round bars from Ø80 to Ø800 mm up to 6,000 mm long, discs and tube sheets from Ø200 to Ø2,500 mm, and shafts, sleeves and blocks up to 6,000 mm long, with unit weights to about 10,000 kg. All work is open-die and made to your drawing, so there is no tooling charge and no minimum order quantity by piece. Send the drawing and we will confirm what is achievable in one piece and what is better split.
Do you supply a material certificate with NW4400 forgings?
Yes. Every NW4400 forging ships with an EN 10204 3.1 mill test certificate as standard, showing the heat number, chemical analysis, mechanical test results, heat treatment record and NDT results. EN 10204 3.2 certification witnessed by a third party such as TÜV, BV, LR, SGS or DNV is available on request at the time of order. Full heat traceability and hard stamping are included.
How long does an NW4400 forging take to produce?
Lead time depends on whether the grade is in raw stock and on the size of the forging. Simple rings and discs from stock material typically run 25–40 days. Parts needing a new melt, ESR remelting, heavy machining or third-party witnessed inspection take longer. Send your drawing and we will confirm a firm date with the quotation.
Who manufactures open-die forged NW4400 parts in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory located at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It forges NW4400 (UNS N04400) and other nickel alloys, stainless steels, tool steels, alloy steels and carbon steels into seamless rolled rings, flanges, bars, discs, shafts, sleeves and tube sheets, and exports worldwide. Enquiries: sales@steelforgepieces.com or +86 189 2135 9659.
17 / Enquiry
Request a quotation for NW4400 forgings
Send a drawing, a sketch, or just the dimensions and quantity. We quote open-die forgings in NW4400 with no tooling charge and no piece minimum.
Useful details if you have them: grade and standard (NW4400 / UNS N04400 / ASTM B564), product form, dimensions with machining allowance, quantity, delivery condition, NDT class, certificate type (EN 10204 3.1 or 3.2), any magnetic permeability or sour-service requirement, and the required delivery date.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Business
- Open-die forging factory
- Address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone
- +86 189 2135 9659
- +86 189 2135 9659
- Website
- www.steelforgepieces.com
- Response time
- Quotation within 24 hours on working days