What is the lead time for custom Monel 400 forged components?

For in-stock raw material sizes the lead time is 45 days. For fully custom Monel 400 forgings the lead time is 60 days. We will ship all forgings in time to our global customers in the USA, EU, UK, Australia and Middle East.

Does Monel 400 (UNS N04400) meet ASME and API standards?

Yes. Jiangsu Liangyi's Monel 400 forgings comply with ASTM B164 / ASME SB-164 for chemical and mechanical properties, API 6A for oil and gas wellhead equipment, ASME Section III for nuclear applications, and ABS Rules for marine structures.

Can you provide third-party inspection for Monel 400 forgings?

Yes. Jiangsu Liangyi offers third-party inspection by TUV, DNV, ABS, BV (Bureau Veritas) and Lloyd's Register. A full EN 10204-3.2 Inspection Certificate is provided with every shipment.

What sizes and product forms of Monel 400 forgings are available?

Jiangsu Liangyi manufactures Monel 400 forged bars (round, square, flat, hollow), seamless rolled rings, discs, flanges, pump and propeller shafts, valve bodies, tube sheets, nozzles, and custom pressure vessel components. All dimensions are available per customer drawing.

What is the difference between Monel 400 and Monel K-500?

Monel 400 (UNS N04400) is an annealed solid-solution alloy with tensile strength 517–620 MPa, excellent weldability and good cost-effectiveness. Monel K-500 (UNS N05500) adds aluminium (2.3–3.15%) and titanium (0.35–0.85%) for age-hardening capability, raising tensile strength to 900–1100 MPa. Choose Monel 400 when weldability and cost are priorities; choose Monel K-500 when higher strength is required.

What heat treatment is applied to Monel 400 forgings?

Monel 400 forgings are full annealed at 870–982 °C (1600–1800 °F) in a sulfur-free atmosphere for complete recrystallisation. Stress relieving at 538–566 °C (1000–1050 °F) for 1–2 hours is applied when residual stresses must be minimised without grain growth.

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Monel 400 (also known as UNS N04400) Forged Parts — Custom Alloy 400 Forgings

📌 Monel 400 Forgings — Basic Information

Material: Monel 400 (also known as UNS N04400, Alloy 400, W.Nr. 2.4360) — Ni 63–70 wt%, Cu 28–34 wt%
Forging Standard: ASTM B564 / ASME SB-564 · AMS 4675 (aerospace)
Bar / Billet Standard: ASTM B164 / ASME SB-164
Tensile Strength (Annealed): 517–620 MPa (75–90 ksi)
Density: 8.80 g/cm³ | Melting Range: 1300–1350 °C
Max Service Temperature: 500 °C (932 °F)
Seawater Corrosion Rate: < 0.025 mm/year
Certifications: ISO 9001, ASTM B564 / ASME SB-564, AMS 4675, API 6A, EN 10204-3.1/3.2, ABS, DNV, BV
Lead Time: 45 days (standard) / 60 days (fully custom)
Shipping: FOB Shanghai / CIF main ports; USA, EU, UK, Australia, Middle East
Manufacturer: Jiangsu Liangyi, Jiangyin City, Jiangsu, China — founded 1984

Jiangsu Liangyi is a leading manufacturer of Monel 400 (UNS N04400) forged components with more than 40 years of production experience. We mainly produce custom Alloy 400 open-die forgings and seamless rolled rings for the marine, chemical, nuclear, and oil & gas industries, supplying customers across the USA, EU, UK, Australia, and the Middle East.

Monel 400 forged round bar, 150 mm diameter, annealed condition, produced by Jiangsu Liangyi — Monel 400 Forged Round Bar

UNS N04400 seamless rolled ring, OD 600 mm, manufactured at Jiangsu Liangyi facility — Monel 400 Seamless Rolled Ring

Marine propeller shaft in Monel 400, ABS certified, for offshore and shipbuilding applications — Monel 400 Marine Propeller Shaft

Alloy 400 forged valve body for oil and gas wellhead equipment, API 6A certified — Monel 400 Forged Valve Body

What Is Monel 400 (UNS N04400)?

Definition: Monel 400 (UNS N04400, also called Alloy 400 or W.Nr. 2.4360) is a nickel-copper solid-solution alloy which contains 63–70% nickel and 28–34% copper, governed by ASTM B564 / ASME SB-564 (forgings) and ASTM B164 / ASME SB-164 (bar and rod). It is one of the most widely used corrosion-resistant alloys in heavy industry, originally developed by the International Nickel Company and named after company founder Ambrose Monell.

Main characteristics that make Monel 400 the best choice for many industries:

It has great resistance to seawater and chloride environments — corrosion rate < 0.025 mm/year in seawater
It has good resistance to hydrofluoric acid (below 80 °C), alkaline solutions and it can reduce the acid media
It has high strength and toughness at a wide temperature range — from cryogenic service to 500 °C (932 °F)
It has single-phase solid-solution microstructure — no sensitization risk during welding or heat treatment
It has good weldability (GTAW, GMAW, SMAW) and machinability in the annealed condition

Monel 400 (UNS N04400) Forged Product Range

Jiangsu Liangyi manufactures a full range of Monel 400 forged products in standard and custom sizes to meet the requirements of different global industries.

Bars & Rods: Round, square, flat, rectangular, hollow bars (UNS N04400 forged bars)
Rings: Seamless forged rings, custom-made sizes (Monel 400 seamless rolled rings)
Housings & Sleeves: Hubs, housing shells, sleeves, bushes, bushing cases, casings
Plates & Blocks: Discs, blocks, forged plates
Pipes & Tubings: Forged pipes, tubes, piping shells, casings, pressure vessel housings
Shafts: Pump shafts, propeller shafts (Monel 400 marine propeller shafts), splined drive shafts and valve spindles
Valve Parts: Valve balls, bonnets, bodies, seat rings (Monel 400 valve parts)
Flanges & Fittings: Channel flanges, double studded adapter flanges, inbuilt mud flanges
Pressure Vessel / Heat Exchanger Parts: Tube sheets, baffle plates, nozzles, boiler/reactor forgings
Nuclear & Oilfield Parts: Reactor coolant pump parts, wellhead spool bodies
Other Forgings: Couplings, cryogenic valve shafts, ultrasonic flow meter bodies

📩 Need a custom Monel 400 forging? Send us your drawing — we respond within 24 hours.

📄 Request a Quote (RFQ)

Monel 400 (UNS N04400) Forged Parts — Industry Uses

Jiangsu Liangyi's Monel 400 forged parts serve demanding uses across many industries worldwide:

Marine and Shipbuilding: Propeller shafts, fasteners and seawater pump parts — ABS / DNV certified
Chemical Processing: Reactors, process pumps, valves and heat exchangers — EN 10204-3.1/3.2
Oil & Gas: Wellhead Christmas trees, mud motors, submersible pumps, compressors — API 6A
Nuclear Power: Reactor coolant pumps, nuclear-grade pressure vessel forgings — ASME Section III
Power Generation: Turbines, turbo machinery, heat exchangers and boiler parts — ASTM B564
General Engineering: Valves, mechanical seal discs and custom heavy-duty machine forgings

Production standards: Marine — ABS Rules | Oil & Gas — API 6A / ISO 13628-4 | Nuclear — ASME Section III | Chemical — ASTM B164

Monel 400 Forgings — Case Studies

Case Study 1 — U.S. Oil & Gas Company: Monel 400 Wellhead Valve Bodies (API 6A)

Project BackgroundAn independent oil producer in Texas required 48 valve bodies for high-pressure acidic gas wellheads with a working pressure of 103 MPa (15,000 psi) and the presence of H₂S.

Technical ChallengePrevious 316L stainless valve bodies showed pitting corrosion and SCC within 18 months. The customer needed API 6A PSL-3G certified components with NACE MR0175 compliance and UT inspection to ASTM E428.

Jiangsu Liangyi SolutionSupplied Monel 400 (UNS N04400) open-die forged valve bodies per ASTM B564 / ASME SB-564. Full annealing at 927 °C; 100% UT per ASTM A388; NACE MR0175 hardness < 35 HRC confirmed; TUV EN 10204-3.2 certificates issued.

Result & DeliveryAll 48 valve bodies delivered FOB Houston within 45 days. 3-year field service follow-up confirmed zero corrosion incidents and maintenance cost reduced by over 70% vs. previous 316L components.

"The delivery was on time, the UT report was clean and the TUV 3.2 certificate was undoubtedly accepted by our client's inspectors." — Procurement Manager, Texas, USA

Case Study 2 — Australian Shipyard: Monel 400 Marine Propeller Shafts (ABS / DNV)

Project BackgroundA Western Australia offshore vessel operator ordered 12 Monel 400 propeller shafts — OD 180 mm × 4,200 mm length — for a fleet of offshore support vessels operating in the Timor Sea.

Technical ChallengeHigh-chloride tropical seawater environment required < 0.025 mm/year corrosion rate, with ABS and DNV-GL dual certification, and shaft straightness ≤ 0.5 mm/m over full length.

Jiangsu Liangyi SolutionOpen-die forged Monel 400 round bars, full annealed. Corrosion rate confirmed at 0.018 mm/year by independent immersion test (ASTM G31, 90 days, 3.5% NaCl). Straightness 0.3 mm/m achieved. ABS and DNV-GL dual certificates issued.

Result & Delivery12 shafts shipped CIF Fremantle within 42 days.After four consecutive years of service in seawater, there were no records of pitting corrosion, crevice corrosion or measurable dimensional changes during the annual dry dock inspection.

"Corrosion data from the immersion test exceeded our specification. The ABS surveyor approved the 3.2 certificates on first review." — Chief Engineer, Perth, Australia

Case Study 3 — German Chemical Plant: Monel 400 Seamless Rolled Rings (EN 10204-3.2)

Project BackgroundA leading specialty chemicals producer in Germany required 20 Monel 400 seamless rolled rings for rotating flange connection of a 70% HF acid alkylation reactor, which had an OD of 620 mm × ID 480 mm × H 90 mm and a working temperature of 65 °C.

Technical ChallengesStrict size tolerance (OD ±2 mm) and comprehensive PMI traceability in accordance with DIN EN ISO 14284 were required, with EN 10204-3.2 inspection witnessed by a third party. Compliance with the German Pressure Equipment Directive (PED 2014/68/EU) was mandatory.

Jiangsu Liangyi SolutionSeamless ring rolling is carried out using Monel 400 billets certified by ASTM B564 / ASTM B164. Fully annealed at 954 °C. OD tolerance achieved ±1.5 mm. TUV SÜD-witnessed inspection; PED-compliant 3.2 certificate issued. PMI report included for every ring.

Result & Delivery20 rings shipped DAP Hamburg in 52 days. After 5 years of continuous HF acid service at 65 °C, measured corrosion rate 0.04 mm/year — well within the 0.10 mm/year design limit. Zero unplanned shutdowns.

"The TUV 3.2 certificates and PMI reports were fully compliant with our QA requirements. The rings have been in HF service for five years with no issues whatsoever." — Plant Engineer, Frankfurt, Germany

Monel 400 Material Selection Guide — When to Choose & When to Upgrade

Common Procurement Mistakes to Avoid

⚠ Mistake 1 — Substituting Monel 400 for 316L Stainless in HF Service
316L stainless steel corrodes rapidly in hydrofluoric acid (HF) at even low concentrations. Monel 400 is the industry standard alloy for HF alkylation units and HF acid pipelines. Direct substitution with 316L usually leads to accelerated pitting corrosion, stress corrosion cracking and part failure within a few months.

⚠ Mistake 2 — Using Monel 400 in Oxidising Acid Environments
Monel 400 is a reducing-environment alloy. In concentrated nitric acid (HNO₃) or fuming sulfuric acid — both strongly oxidising — corrosion rates become unacceptably high. The correct alloy for oxidising acids is Inconel 625 or Hastelloy C-276.

⚠ Mistake 3 — Ignoring the risk of stress corrosion cracking (SCC) in wet chlorine uses
Monel 400 is susceptible to SCC in damp, aerated hydrofluoric acid vapor and high-temperature mercury-containing environments. Always confirm the operating medium and temperature before specifying Monel 400 for new projects.

Monel 400 vs. Inconel 625 vs. Hastelloy C-276 — Selection Decision Guide

Choose Monel 400 (UNS N04400) when:

Seawater / marine service HF acid process equipment Alkaline / caustic environments Cryogenic to 500 °C service Cost-sensitive project Good weldability required

Upgrade to Inconel 625 (UNS N06625) when:

Service temperature > 500 °C Oxidising acid exposure Higher tensile strength required Mixed acid / aggressive chloride

Upgrade to Hastelloy C-276 (UNS N10276) when:

Wet chlorine gas service Oxidising + reducing mixed acids Chloride stress corrosion risk FGD / flue gas desulfurisation

Monel 400 (UNS N04400) — Technical Specifications

Applicable Standards for Monel 400 Forged Components:

ASTM B564 / ASME SB-564 — Nickel Alloy Forgings: the primary standard governing open-die forgings and seamless rolled rings.It covers the inspection requirements for chemical composition, mechanical properties, heat treatment and forged parts.
AMS 4675 — Monel 400 Forgings (Aerospace): SAE Aerospace Material Specification for Monel 400 forgings used in aerospace and defense uses. Specifies tighter grain size control and additional qualification requirements.
ASTM B164 / ASME SB-164 — Nickel-Copper Alloy Rod, Bar and Wire: applies to the raw material billet used in our forging process, and to forged bar/rod product forms.

Chemical Composition — Monel 400 (UNS N04400)

Test Standard: ASTM B564 / ASME SB-564 (forgings) | ASTM B164 / ASME SB-164 (bar & rod)

Monel 400 (UNS N04400) Chemical Composition (wt%)
Element	C	Mn	Si	S	Cu	Ni	Fe
Content (wt%)	0.30 max	2.00 max	0.50 max	0.024 max	28.0–34.0	63.0–70.0	2.50 max

Mechanical Properties — Monel 400 Annealed Condition

Test Standard: ASTM B564 / ASME SB-564 (forgings) | ASTM B164 / ASME SB-164 (bar & rod)

1 MPa = 0.145 ksi | 1 GPa = 145 ksi

Monel 400 (UNS N04400) Mechanical Properties (Annealed)
Property	Metric	Imperial
Tensile Strength	517–620 MPa	75–90 ksi
Yield Strength (0.2% offset)	172–345 MPa	25–50 ksi
Modulus of Elasticity	179 GPa	26,000 ksi
Poisson's Ratio	0.32	0.32
Elongation (min)	35%	35%
Hardness (typical)	65–85 HRB	65–85 HRB

Physical Properties — Monel 400 (UNS N04400)

Monel 400 (UNS N04400) Physical & Thermal Properties
Property	Value (Metric)	Value (Imperial)
Density	8.80 g/cm³	0.318 lb/in³
Melting Range	1300–1350 °C	2372–2462 °F
Thermal Expansion (20–100 °C)	13.9 µm/m·°C	7.7 µin/in·°F
Thermal Conductivity (20 °C)	21.8 W/m·K	151 BTU·in/hr·ft²·°F
Specific Heat (20 °C)	427 J/kg·K	0.102 BTU/lb·°F
Electrical Resistivity (20 °C)	0.511 µΩ·m	20.1 µΩ·in
Magnetic Permeability	~1.001 (non-magnetic)	~1.001

Monel 400 Corrosion Resistance — Performance in Various Media

Monel 400 (UNS N04400) Corrosion Resistance in Key Process Media
Corrosive Medium	Condition	Performance	Typical Application
Seawater (flowing)	Ambient, flowing	✔ Excellent < 0.025 mm/yr	Marine propeller shafts, fasteners
Seawater (stagnant)	Stagnant, risk of crevice	△ Good — avoid crevices	Design to eliminate stagnant zones
Hydrofluoric Acid (HF)	All conc., below 80 °C	✔ Excellent	HF alkylation units, valves, pumps
Hydrofluoric Acid (HF)	Above 80 °C	△ Moderate — verify with test	High-temp HF service (consult engineer)
Hydrochloric Acid (HCl)	Dilute, de-aerated, RT	✔ Good	Pickling equipment
Hydrochloric Acid (HCl)	Concentrated or aerated	✘ Not recommended	—
Sulfuric Acid (H₂SO₄)	Dilute, de-aerated, RT	✔ Good	Process equipment
Sulfuric Acid (H₂SO₄)	Concentrated or hot	✘ Not recommended	—
Phosphoric Acid (H₃PO₄)	Dilute, non-oxidising	✔ Good	Fertiliser / food processing
Caustic Soda (NaOH)	All concentrations	✔ Excellent	Alkali process equipment
Ammonia / Amines	Anhydrous or aqueous	✔ Excellent	Ammonia handling, refrigeration
Acetic Acid	All concentrations, RT	✔ Good	Food & pharmaceutical processing
High-Temperature Steam	Up to 500 °C	✔ Excellent	Nuclear & power generation
Nitric Acid (HNO₃)	Any concentration	✘ Not recommended	Use Inconel 625 instead
Moist Chlorine Gas (Cl₂)	Wet or moist	✘ Not recommended (SCC risk)	Use Hastelloy C-276 instead

Monel 400 in Hydrofluoric Acid — Corrosion Rate vs. Temperature

Monel 400 is the preferred alloy for HF service. Corrosion rate increases significantly above 80 °C:

Monel 400 (UNS N04400) — Approximate Corrosion Rate in HF Acid (mm/year)
HF Concentration	20 °C	50 °C	80 °C	> 80 °C
10%	< 0.03	< 0.05	< 0.10	0.10–0.50 (verify)
40%	< 0.02	< 0.05	< 0.13	0.13–0.60 (verify)
70%	< 0.03	< 0.05	< 0.15	Contact engineer
Anhydrous HF	< 0.02	< 0.03	0.08–0.20	Contact engineer

Note: Values are indicative based on published literature. Actual rates depend on flow velocity, oxygen content, and specific plant conditions. Contact our engineering team for project-specific assessment.

Stress Corrosion Cracking (SCC) Risk in Monel 400

Monel 400 has a strong track record in most corrosive environments, but SCC susceptibility must be considered in two specific conditions:

Moist hydrofluoric acid vapour above 100 °C: Aerated HF vapour can cause SCC in Monel 400 under stress. For high-temperature HF vapour service, use stress-relieved forgings and design to minimise tensile stress at exposed surfaces.
Mercury-contaminated environments: Mercury causes liquid metal embrittlement (LME) in nickel-copper alloys. Monel 400 should not be used in process streams with mercury contamination above trace levels (e.g. certain natural gas streams).

In all standard seawater, chemical, nuclear and oil & gas applications within the specified temperature range, Monel 400 forgings from Jiangsu Liangyi have demonstrated zero SCC failures under 40+ years of field service.

Monel 400 Forged Parts — Typical Dimensional Tolerances

Tolerances per ASTM B564 / customer drawings. Tighter tolerances available on request.

Monel 400 Forging Dimensional Tolerances (Standard)
Product Form	Dimension Range	Typical Tolerance	Standard Reference
Round Forged Bar (OD)	25–250 mm	±1.5 mm	ASTM B564
Round Forged Bar (OD)	250–600 mm	±3.0 mm	ASTM B564
Seamless Rolled Ring (OD)	100–2000 mm	±3 mm (OD) / ±2 mm (H)	Per drawing
Forged Disc / Plate (thickness)	20–200 mm	+3 / −0 mm	Per drawing
Forged Shaft (straightness)	Any length	≤ 1 mm/m	Per drawing

Monel 400 vs. Monel K-500 — Selection Guide

Choosing Monel 400 or Monel K-500 depends on required strength and weldability:

Monel 400 (UNS N04400) vs. Monel K-500 (UNS N05500)
Property	Monel 400 (UNS N04400)	Monel K-500 (UNS N05500)
Ni Content	63–70%	63–70%
Cu Content	28–34%	27–33%
Al + Ti additions	None	Al 2.3–3.15%; Ti 0.35–0.85%
Tensile Strength	517–620 MPa	900–1100 MPa
Yield Strength	172–345 MPa	620–760 MPa
Hardening Mechanism	Cold work only	Age-hardening (precipitation)
Weldability	Excellent	Good (post-weld age required)
Corrosion Resistance	Excellent	Excellent (similar)
Forging Standard	ASTM B564 / AMS 4675	ASTM B564 / AMS 4676
Best For	Valves, heat exchangers, pump casings	High-torque shafts, springs
Relative Cost	Lower	Higher (~20–30%)

Monel 400 vs. Duplex 2205 vs. Titanium Grade 2 — Uses Comparison

For seawater and chemical uses, buyers often compare Monel 400 with Duplex 2205 stainless steel and Titanium Grade 2. The table below outlines the main differences:

Monel 400 vs. Duplex 2205 vs. Titanium Grade 2 — Material Selection
Property	Monel 400 (UNS N04400)	Duplex 2205 (UNS S32205)	Titanium Grade 2 (UNS R50400)
Tensile Strength	517–620 MPa	620–860 MPa	345–485 MPa
Yield Strength	172–345 MPa	450–650 MPa	275–380 MPa
Density	8.80 g/cm³	7.80 g/cm³	4.51 g/cm³
Seawater Resistance	Excellent (flowing)	Good (low velocity)	Excellent
HF Acid Resistance	Excellent	Poor	Not recommended
Chloride SCC Resistance	Excellent	Moderate (pitting risk)	Excellent
Max Service Temp.	500 °C	300 °C (duplex limit)	315 °C
Weldability	Excellent	Good (needs PWHT control)	Good (inert atmosphere)
Forgeability	Excellent	Good	Moderate (cost premium)
Relative Material Cost	Medium	Medium-Low	High
Best For	HF acid, seawater, nuclear	Structural, offshore, general marine	Aerospace, medical, oxidising acid

How Monel 400 Forgings Are Manufactured — Step-by-Step Process

Every Monel 400 forging at Jiangsu Liangyi follows a rigorous 10-step production process to ensure full traceability and compliance with international standards.

Raw Material Verification: PMI (Positive Material Identification) test the chemistry of ASTM B564 / ASTM B164-certified billet and mill certificate. Heat number will be written down so that it could be traced back to its source.
Billet Heating: Billets heated to 900–1150 °C in a sulfur-free furnace atmosphere to ensure uniform temperature distribution and prevent surface contamination.
Open-Die Forging / Seamless Ring Rolling: Correct reduction ratios can help to get continuous grain flow, eliminate porosity and ensure mechanical property uniformity throughout the cross-section.
Full Annealing Heat Treatment: Anneal in a sulfur-free atmosphere at 870-982°C (1600-1800°F) to complete recrystallization. Relieve stress at 538-566°C for 1-2 hours as needed.
Rough Machining & Size Inspection: Near-net-shape machining and tested as per clients' drawing.
Non-Destructive Testing (NDT): Ultrasonic testing (UT according to ASTM A388) + surface crack detection (MT or PT). Results recorded in the test certificate.
Mechanical Testing: Tensile, yield, elongation and Brinell/Rockwell hardness tests on samples from the same heat per ASTM B564 / ASME SB-564.
Chemical Analysis: Complete spectral analysis makes sure that the Ni content is 63-70%, the Cu content is 28-34%, and the contents of all trace elements meet the ASTM B564 / ASTM B164 standard.
Third-Party Inspection & Certification: Inspected by TUV, DNV, ABS or BV as specified. EN 10204-3.1 or 3.2 certification issued.
Export Packing & Shipment: Export packing as per ISPM 15 . FOB Shanghai or CIF main ports; 45–60 days delivery.

Monel 400 (UNS N04400) Heat Treatment

Heat treatment is strictly controlled for every Monel 400 open-die forging to ensure optimal mechanical properties and corrosion resistance.

Full Annealing: 870–982 °C (1600–1800 °F) in a sulfur-free atmosphere. Lower end of range makes finer grain size.
Stress Relieving: 538–566 °C (1000–1050 °F) for 1–2 hours — relieves residual forging stresses without recrystallisation.
Open-Die Forging & Seamless Ring Rolling: The right forging temperature ensures grain-flow continuity and structural integrity in all Alloy 400 forged rings.

Monel 400 Machinability & Welding Guide

Monel 400 can be machined and welded successfully with correct procedures. Its primary challenge is a strong tendency to work-harden during cutting, which requires sharp tooling and steady, consistent feeds.

Monel 400 Processing Suggestions

🔧 Cutting Tools

Hard alloy tool heads or hard alloy cutting tools are preferred
High-speed steel (HSS) is suitable for low-speed operations
Positive rake Angle (8-15°) reduces the work hardening
Sharp cutting edge - Change the tool before wear causes friction
Try to avoid interrupting the cutting

⚙Cutting Parameters

Turning (hard alloy):30 to 75 meters per minute, with a feed rate of 0.15 to 0.40 millimeters per revolution
Milling (cemented carbide):20-50m /min, feed 0.10-0.25 mm/ tooth
Drilling:8-15 meters per minute, feed rate 0.08-0.18 millimeters per revolution
To keep the tool from staying, keep the chips in contact with each other
To get the next work-hardened layer, use a deep cut

💧 Coolant

High-strength sulfurized or sulfurous chloride cutting oil for turning/drilling
Water-soluble coolant suitable for milling (10-15% concentration)
Flood coolant — never dry machine Monel 400
Make sure the coolant reaches the cutting area, not just the chips

⚠ Work Hardening — Main Warnings

Monel 400 has rapid work hardening - it is harder than 316L stainless steel
Never let the tools rub against or stay in place - this will cause the skin to harden and make the next level sluggish
Try to keep the machine in an annealed state
If re-hardening occurs,complete annealing at 870-980°C is required before proceeding

Monel 400 Welding Guide

🔩 Recommended Filler Metals

GTAW (TIG): ERNiCu-7 (Alloy 60 / Monel filler wire)
GMAW (MIG): ERNiCu-7
SMAW (stick): ENiCu-7 (coated electrode)
All per AWS A5.14 / SFA 5.14 (ASME)
Do not use stainless steel filler — causes galvanic incompatibility

🌡 Preheat & Interpass Temperature

Preheat: Not required for base metal < 25 mm thickness
For heavy sections (> 25 mm): warm to 100–150 °C
Maximum interpass temperature: 150 °C
Minimize heat input — use stringer beads, not weave
Back-purge with argon for GTAW root passes

✅ Post-Weld Treatment

Full anneal at 870–982 °C recommended for pressure-retaining welds
Stress relieve at 538–566 °C / 1–2 hrs if full anneal not practical
Remove all weld spatter — it can initiate pitting in corrosive media
Pickle or passivate weld HAZ for seawater or HF acid service

⚠ Prevention of Common Welding Defects

Hot cracking: Caused by sulfur contamination — ensure that the base material and mold are sulfur-free
Porosity: Use clean, dry fillers; store the electrodes in accordance with the manufacturer's instructions
Lack of integration: Slightly increase the speed of progress; Avoid over-weaving
Heat-affected zone sensitization:Monel 400 (single-phase alloy) does not need to be considered

Quality Assurance and Certifications

Each batch of Monel 400 forgings undergoes strict quality inspection and is accompanied by complete certification documents. Jiangsu Liangyi is an ISO 9001-certified manufacturer.

✓ ASTM B564 / ASME SB-564 Nickel Alloy Forgings
✓ AMS 4675 Monel 400 Forgings — Aerospace
✓ ASTM B164 / ASME SB-164 Nickel-Copper Alloy Bar and Rod
✓ ISO 9001 Quality Management System
✓ EN 10204-3.1 Mill Test Certificate (MTC)
✓ EN 10204-3.2 Inspection Certificate (TUV, GL, BV, DNV, ABS, Lloyd's Register)
✓ API 6A — Wellhead and Christmas Tree Equipment
✓ ABS — American Bureau of Shipping (marine)
✓ DNV — Det Norske Veritas (marine / offshore)
✓ ASME Section III — Nuclear Components

Monel 400 Forged Parts — Full Test Certificate includes

Heat number and melting method
Dimensional inspection results
Full heat treatment process record
Chemical composition analysis
Mechanical test results (hardness, tensile, yield, elongation)
Ultrasonic testing (UT) and surface crack detection (MT/PT) results
Surface inspection
Client's other additional tests per drawing or purchase order

Why Choose Jiangsu Liangyi as Your Monel 400 Forgings Manufacturer?

⭐ 40+ Years of Experience (since 1984): Over four decades of proven expertise in Monel 400 open-die forging, with components delivered to customers in more than 50 countries.
⭐ Fully Custom Production: All Monel 400 forgings are manufactured to customer drawings — any shape, any dimension, with no minimum order quantity.
⭐ Strict Quality Control: ISO 9001 certified; all testing is conducted in-house and independently verified by accredited third-party inspectors including TUV, DNV, ABS, and Bureau Veritas.
⭐ On-Time Delivery: 45-day standard lead time with a proven track record of reliable, on-schedule delivery to customers in the USA, EU, UK, Australia, and the Middle East.
⭐ Competitive Pricing: As a direct manufacturer with no intermediaries, we offer highly competitive pricing on premium-quality Monel 400 forgings — without compromising on specification compliance.
⭐ Full Traceability: EN 10204-3.1/3.2 certificates; heat traceability from melt to finished forging.
⭐ Professional Engineering Support: Our metallurgical engineers bring deep expertise in nickel alloy processing and are available to assist with material selection, drawing review, and full technical consultation.

Frequently Asked Questions (FAQs) — Monel 400 Forgings

Q: What is Monel 400 ( also known as UNS N04400)?

A: Monel 400 (UNS N04400, Alloy 400) is a nickel-copper solid-solution alloy which contains 63–70% nickel and 28–34% copper, governed by ASTM B564 / ASME SB-564 (forgings) and ASTM B164 / ASME SB-164 (bar and rod). It has great resistance in seawater (< 0.025 mm/year), hydrofluoric acid and alkaline environments, with a service temperature from cryogenic to 500 °C (932 °F).

Q: What are the physical properties of Monel 400?

A: Monel 400 (UNS N04400) physical properties are as below: Density 8.80 g/cm³ (0.318 lb/in³); Melting range 1300–1350 °C (2372–2462 °F); Thermal expansion coefficient 13.9 µm/m·°C (20–100 °C); Thermal conductivity 21.8 W/m·K at 20 °C; Specific heat 427 J/kg·K; Electrical resistivity 0.511 µΩ·m.

Q: How does Monel 400 work in corrosive media?

A: Monel 400 works well in seawater (corrosion rate < 0.025 mm/year), hydrofluoric acid (below 80 °C), dilute hydrochloric acid (room temperature), alkaline solutions (NaOH), and high-temperature steam up to 500 °C. It is not recommended for use in strong oxidising acids such as concentrated nitric acid or fuming sulfuric acid.

Q: What is the lead time for custom Monel 400 forgings?

A: Normally 45 days for standard sizes if stock raw material available, and 60 days for fully custom Monel 400 forgings. We make sure on-time delivery to our global customers in the USA, EU, UK, Australia and Middle East.

Q: Do Monel 400 forgings comply with ASME and API standards?

A: Yes. Our Monel 400 forgings comply with ASTM B564 / ASME SB-564 (the primary nickel alloy forging standard), AMS 4675 (aerospace forgings) and ASTM B164 / ASME SB-164 (bar and rod). The forgings also comply with other certifications including API 6A (oil and gas), ASME Section III (nuclear) and ABS / DNV Rules (marine).

Q: Can you accept third-party inspection?

A: Yes.We can accept inspections by third-parties such as TUV, DNV, ABS, BV (Bureau Veritas) and Lloyd's Register. We will provide the EN 10204-3.2 inspection certificate for each batch of forgings.

Q: What are the differences between Monel 400 and Monel K-500?

A: Monel 400 (UNS N04400) is an annealed alloy (tensile strength 517–620 MPa) with good weldability. Monel K-500 (UNS N05500) adds Al (2.3–3.15%) and Ti (0.35–0.85%) for age-hardening, raising tensile strength to 900–1100 MPa. Choose Monel 400 when weldability and cost are priorities; choose Monel K-500 when higher strength is required.

Q: How is Monel 400 forging manufactured step by step?

A: Monel 400 open-die forging is produced in 10 steps: (1) PMI raw material verification; (2) Heating to 900–1150 °C; (3) Open-die forging or ring rolling; (4) Annealing at 870–982 °C; (5) Rough machining & CMM inspection; (6) UT + MT/PT NDT testing; (7) Mechanical testing per ASTM B564 / ASME SB-564; (8) Chemical analysis; (9) Third-party inspection & EN 10204-3.2 certificate; (10) Export packing and global shipment in 45–60 days.

Q: What kind of heat treatment is suitable for Monel 400 forgings?

A: Monel 400 forgings are full annealed at 870–982 °C (1600–1800 °F) in an atmosphere without sulfur so that they can fully recrystallize and be resistant to corrosion as possible. Stress relieving at 538–566 °C (1000–1050 °F) for 1–2 hours is done when you need to reduce residual stresses without making the grains grow.

Q: What is the approximate price of Monel 400 forgings per kg?

A: The price of Monel 400 forgings varies with the global nickel and copper market prices, the complexity of the forgings, the quantity and the certification requirements. As a general guideline, the price of standard Monel 400 forged bars and rings is usually between $25 and $55 per kilogram, depending on the size and specification. Custom shapes, heavy-section forgings, or those requiring EN 10204-3.2 / API 6A certification carry a premium. Contact us with your drawing and quantity for a firm quotation within 24 hours.

Q: What is the maximum size of the forgings that Jiangsu Liangyi can make of Monel 400?

A: We can produce Monel 400 open-die forgings up to about 8,000 kg per piece. For seamless rolled rings, we can get an outer diameter of up to 3,000 millimeters. For forged bars and shafts, lengths up to 6,000 mm are achievable. Maximum dimensions are subject to raw material availability and furnace capacity. Please send your drawing for confirmation.

Q: Can Monel 400 forgings be supplied to NACE MR0175 / ISO 15156?

A: Yes. Monel 400 (UNS N04400) is included in NACE MR0175 / ISO 15156-3 for use in sour oil and gas environments (H₂S-containing).The hardness of our Monel 400 forgings is controlled at ≤35 HRC (or ≤35 HRB), and there are complete mechanical test records confirming compliance with the requirements. According to the requirements, indicate compliance with NACE MR0175 on the en10204-3.1 or 3.2 test certificate.

Q: What is the difference between Monel 400 and Monel 404?

A: Monel 400 (UNS N04400) is a standard commercial alloy with a Ni content of 63-70% and a Cu content of 28-34%. It is widely used in the chemical, marine, nuclear energy and oil and gas industries. Monel 404 (UNS N04404) is a low-permeability variant with stricter composition control (especially lower iron and silicon content), specifically developed for uses that require extremely low permeability - such as magnetic compass housings and instrument components.For all standard structural and chemical process uses, Monel 400 is the correct choice. Monel 404 is a specialty product produced in limited quantities.

Q: Do you hold Monel 400 forging stock? What standard sizes are available?

A: Jiangsu Liangyi maintains raw material billet stock of Monel 400 (UNS N04400) certified to ASTM B564 / ASTM B164, which significantly reduces lead times. Common near-net forged sizes available from stock billet include round bars from 50 mm to 500 mm diameter, and seamless rings from OD 150 mm to OD 1,000 mm. For standard sizes from stock billet, lead time is typically 30–35 days. Contact us with your target dimensions and we will confirm stock availability and the fastest possible lead time.

Monel 400 (UNS N04400) Forged Components — Global Supply

Jiangsu Liangyi supplies precision custom Monel 400 forgings to customers worldwide. As one of China's most experienced Monel 400 forging manufacturers, we offer competitive pricing, good lead times and dependable delivery to the USA, EU, UK, Australia and the Middle East.

Other Forged Parts:
17-4PH Stainless Steel Forgings (UNS S17400 / AISI 630) | Incoloy 825 Forged Parts | Inconel 725 Forgings

Monel 400 — Technical Resources & Downloads

The following resources are available to support your engineering evaluation and procurement process. Contact us to request the document and we will send it to your email within one business day.

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Monel 400 Technical Data Sheet

2-page PDF: chemical composition, mechanical properties, physical properties, heat treatment, and corrosion data per ASTM B564 / ASME SB-564 and ASTM B164 / ASME SB-164.

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RFQ Template

Structured quotation request form — material, dimensions, quantity, standard, certification, and delivery requirements.

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EN 10204-3.2 Certificate Sample

The edited sample inspection certificates, display formats, test data structures and third-party signatories are used for the delivery of our Monel 400.

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