Monel Alloy
Monel Alloy Manufacturer & Supplier | Monel 400/K500 Pipe, Plate, Bar, Fittings | Factory Direct Export
GNEE Alloy is a professional supplier of Monel alloys, maintaining a stock of 1,000 tons and offering grades such as UNS N04400 and N05500 (Monel 400, K500, 401, 404, 405, and 450) in the form of plates, seamless pipes, bars, flanges, and pipe fittings. Our products comply with ASTM B164 and B165 standards, meet NACE MR0175 requirements, and hold EN10204 3.1 certification. We are dedicated to providing timely delivery for projects in the global marine engineering, oil and gas, chemical, and power sectors, while also offering complimentary technical documentation and sample support.
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Gnee Alloy Monel Grade Selection Guide
Click to view technical data sheets and product ranges for specific grades
Monel 400 (UNS N04400) – Standard corrosion-resistant grade; widely used for static equipment in chemical and marine applications
Monel K-500 (UNS N05500) – Precipitation-hardened, high-strength grade; suitable for rotating and high-load components in offshore and oilfield facilities
Monel 405 (UNS N04405) – Free-machining, sulfur-modified grade; suitable for fasteners produced on automatic lathes
Monel 401 (UNS N04401) – Features a low temperature coefficient of resistance; suitable for specialized electronic welding components
Monel 404 (UNS N04404) – Features an extremely low Curie temperature and low magnetic permeability; suitable for transistors and ceramic-to-metal seal components
Monel 450 – High fatigue-resistant grade; suitable for seawater condenser and heat exchanger tubing
Contact our experts to recommend the right alloy for your project
Monel is a proprietary nickel-copper solid-solution alloy. Its primary chemical composition consists of 63%–70% nickel and 28%–34% copper, with strictly controlled levels of trace elements—such as iron (Fe), manganese (Mn), carbon (C), silicon (Si), and sulfur (S)—to tune its mechanical and magnetic properties.
Unlike stainless steel or pure nickel, Monel alloy combines high strength with good ductility and exhibits exceptional corrosion resistance in reducing environments (such as hydrofluoric acid, brine, sour gas, and seawater). Data from third-party laboratory testing is as follows:
Static seawater full-immersion corrosion rate: ≤0.025 mm/year (only one-fifth that of standard 316L stainless steel)
Long-term service temperature range: -200°C to 480°C, with stable mechanical properties and no significant loss of strength
Excellent resistance to chloride-ion stress corrosion cracking; no pitting or crevice corrosion failure occurs in neutral saline environments
Key Procurement Advantages of Gnee Alloy Monel Alloys
**Superior Comprehensive Performance**
Solid-solution strengthening mechanisms enable Monel 400 to achieve a tensile strength of ≥482 MPa in the annealed state and up to 896 MPa in the cold-drawn, hard-temper state; following age-hardening heat treatment, Monel K-500 reaches a tensile strength of 1034 MPa. These figures far exceed those of pure nickel or copper, helping to reduce wall thickness and overall weight in marine engineering and pressure vessel projects.
**Industry-Leading Corrosion Resistance**
These alloys perform exceptionally well in environments involving hydrofluoric acid alkylation units, sulfuric acid, caustic alkalis, saltwater, and H₂S-bearing sour gas; Monel 400 is the only cost-effective alloy suitable for concentrated hydrofluoric acid production lines.
**Versatile Fabrication Capabilities**
Compatible with GTAW, SMAW, and GMAW welding, as well as hot forging (forming temperature range: 648–1176°C), cold rolling, and extrusion processes; Monel 405 features optimized sulfur content specifically designed for high-speed automatic lathe machining, thereby reducing production costs for bulk fastener orders.
**Controllable Magnetic Characteristics**
Monel 401, 404, and K-500 exhibit low magnetic permeability, making them ideal choices for non-magnetic downhole oil tools, electronic sensors, and precision aerospace instruments; Monel 400 has a Curie temperature of 21–49°C and is weakly magnetic at room temperature, so it is not recommended for applications requiring strict non-magnetic properties.
**High Cost-Effectiveness and Long Service Life**
Although the unit price is higher than that of carbon steel, Monel equipment extends maintenance intervals by 8 to 12 times, significantly reducing downtime and replacement costs for large-scale chemical and marine engineering projects; in highly corrosive environments, its total lifecycle cost is lower than that of duplex stainless steel.
Gnee Alloy: Comprehensive Technical Data Library for Monel Alloy Grades
Monel Grade Chemical Composition Standard Table
| Grade | UNS No. | Ni(Min) | Cu | Fe(Max) | Mn(Max) | C(Max) | Si(Max) | S | Special Alloy Elements |
|---|---|---|---|---|---|---|---|---|---|
| Monel 400 | N04400 | 63% | 28~34% | 2.5% | 2.0% | 0.30% | 0.50% | ≤0.024% | None |
| Monel K-500 | N05500 | 63% | 27~33% | 2.0% | 1.5% | 0.08% | 0.50% | ≤0.01% | Al 2.3~3.15%, Ti 0.35~0.85% |
| Monel 405 | N04405 | 63% | 28~34% | 2.5% | 2.0% | 0.30% | 0.50% | 0.025~0.060% | High sulfur for chip breaking |
| Monel 401 | N04401 | 63% | 28~34% | Controlled low Fe | Low Mn | Low C | Low Si | Ultra-low S | Optimized resistance temperature coefficient |
| Monel 404 | N04404 | 63% | Special Cu ratio | Low impurity | Low Mn | Low C | Low Si | Ultra-low S | Low Curie temperature control |
| Monel 450 | Custom | 64% | 29~33% | Low Fe | Low Mn | Low C | Low Si | ≤0.02% | Optimized fatigue & thermal conductivity |
Gnee Alloy Nickel Based Alloy PMI Test
Reference for Key Mechanical Properties of Gnee Alloy Monel Alloys (Annealed/Aged Conditions)
Monel 400 (Annealed): Tensile Strength ≥482 MPa, Yield Strength ≥193 MPa, Elongation ≥35%, Hardness ≤75 HRB
Monel K-500 (Aged): Tensile Strength ≥1034 MPa, Yield Strength ≥724 MPa, Elongation ≥15%, Hardness ≥30 HRC
Monel 405: Machinability improved by 40% compared to Monel 400; surface finish slightly reduced due to sulfide inclusions
Monel 401/404: Electrical resistivity temperature deviation ≤±2% within the -50 to 150°C range
Gnee Alloy Monel Alloy: Global Standards
Pipes/Tubes: ASTM B165, ASME SB163, SB725
Plates/Sheets: ASTM B127, ASME SB127
Bars/Rods: ASTM B164, ASME SB164
Forgings and Flanges: ASTM B564, B366
Industry Specifications: NACE MR0175 / ISO 15156-3 (Sour Oil & Gas Fields), QQ-N-281, BS 3075, DIN 17750, ASTM F96 (Grade 404)
Export Certification Standards: EN10204 3.1 / 3.2 Material Test Certificates, SGS Third-Party Inspection
Comprehensive Monel alloy product portfolio (all grades and forms available in stock)
Monel Piping (Key Export Products)
Grades: Monel 400, K-500
Types: Seamless pipe, bright capillary tubing, ERW (Electric Resistance Welded) pipe, heat exchanger/evaporator tubing
Standards: ASME SB163, ASTM B165
Size Range: OD 3mm–600mm, Wall Thickness 0.5mm–50mm, Length 1m–12m (fixed or random lengths)
Applications: Offshore seawater piping, hydrofluoric acid (HF) alkylation process piping, power plant condenser tubing, brine heaters
Monel Plate and Coil
Grades: 400, K500, 450
Thickness: 0.3mm–100mm (hot-rolled plate, cold-rolled polished plate)
Surface Finish: Pickled, bright polished, sandblasted
Applications: Chemical reactor linings, marine equipment housings, still plates
Monel Bar and Round Stock
Grades: 400, K500, 405 (free-machining grade)
Shapes: Round, square, hexagonal, flat bars
Diameter: 3mm–500mm (bright or black finish available)
Applications: Pump shafts, valve stems, automatic lathe fasteners, oilfield drill collars
Monel Pipe Fittings and Forged Flanges
Products: Elbows, tees, reducers, blind flanges, weld neck flanges, threaded fittings
Standards: ASTM B366, B564
Forging Process: Hot die forging, full heat treatment, 100% UT/MT (Ultrasonic/Magnetic Particle) NDT inspection
Contact us to customize Inconel 625 products to your project's dimensions
Key Industrial Applications of Monel Alloys
Oil & Gas / Offshore Engineering (Largest export market for Monel alloys)
Monel 400: Internal cladding for crude oil distillation towers, seawater cooling piping, wellhead valves and pump bodies, hydrofluoric acid (HF) alkylation reaction piping
Monel K-500: Subsea pump shafts, propeller shafts, oil drill collars, non-magnetic downhole instrument components, sour gas service components compliant with NACE MR0175 standards
Operational Advantages: Resistant to corrosion from high-salinity seawater and H₂S sour gas; long service life in high-pressure deep-sea environments
Marine and Shipbuilding Industries
Seawater condenser tubes, marine seawater piping, propeller shafts, hull fasteners, offshore platform splash-zone equipment, seawater desalination evaporator tubes; annual supply to 15 shipyards worldwide; corrosion rate ≤0.025 mm/year in full seawater immersion
Chemical Processing Plants
Irreplaceable material for concentrated hydrofluoric acid production equipment: alkylation unit reaction piping, pickling tank heating coils, sulfuric acid scrubbing towers, fluoride reactors, pumps and valves for the chlor-alkali industry. Monel 400 significantly outperforms stainless steel in reducing acid media
Electric Power Industry
Boiler feedwater heater tubes, steam generator heat exchangers, brine heaters, nuclear fuel isotope separation equipment, deaerator heater internals, corrosion-resistant cooling piping
Electronics, Aerospace, and Precision Equipment
Monel 401/404: Transistor housings, ceramic-to-metal seals, low-permeability electronic sensor components
Monel K-500: Small, high-strength fasteners for aerospace landing gear, corrosion-resistant auxiliary engine components
Monel 405: Mass-produced fasteners for electronic equipment (manufactured via automatic screw machines)
Contact our experts to recommend the right alloy for your project
| Aspect | Details |
|---|---|
| Extensive Ready‑to‑Ship Inventory | Tianjin warehouse maintains 200,000 tons of Monel alloys (Monel 400 & K500) in pipes, plates, and bars. Orders from small‑batch samples (min. 5 kg) to large‑scale projects (over 1,000 tons) are accommodated. Standard specifications are ready for shipment within 7–15 days. |
| Stable Annual Production Capacity | Total annual superalloy production capacity: 1 million tons. Annual Monel export capacity: 80,000 tons. Capable of handling bulk procurement for major projects such as offshore platforms, oil refineries, and power plants. |
| Global Export Experience & Client Reach | Products exported to over 70 countries and regions, including Southeast Asia, the EU, Australia, the Middle East, and North America. Long‑term partnerships with 15 shipbuilding groups, 143 chemical engineering contractors, and 23 boiler/power machinery manufacturers. Well‑versed in international trade terms (FOB, CIF, DAP) and customs clearance documentation. |
| Comprehensive Quality Control & Third‑Party Inspection | Independent physical/chemical lab equipped with spectrometers, tensile testers, hardness testers, and salt spray chambers. Supports pre‑shipment inspections by SGS, BV, or TUV. Every batch comes with traceable EN10204 3.1/3.2 material test reports (MTR). |
| One‑Stop Export Service System | Professional sales engineering team (18+ years of experience) offers free material selection advice. Dedicated QC team ensures raw material purity. Logistics team handles container loading, anti‑rust protection, and door‑to‑door delivery. Provides full export documentation (commercial invoice, packing list, certificate of origin, and MTR). |
Contact us to learn about our Inconel 625 production process
Gnee Alloy Standard Monel Alloy Manufacturing Process
| Process Step | Description |
|---|---|
| Melting and Alloying | Melting of high‑purity nickel and copper raw materials; precise addition of trace elements (Fe, Mn, Al, Ti, S) per grade standards; thorough homogenization to prevent compositional segregation. |
| Casting | Casting into standard ingots or billets; internal defect inspection to eliminate porosity and cracks. |
| Hot Working | Hot rolling or hot forging within 648–1176°C to refine grain structure. |
| Cold Forming | Cold drawing (tubing), cold rolling (plate/sheet), or extrusion (bars) to ensure precise dimensional tolerances and surface finish. |
| Heat Treatment | Solution annealing, age hardening (for K‑500), and stress‑relief tempering to stabilize mechanical and corrosion‑resistant properties. |
| Precision Finishing | Cutting, polishing, machining, and non‑destructive testing (UT, MT, PT). |
| Final Quality Inspection and Packaging | Dimensional verification; sampling tests for chemical composition and mechanical properties; export packaging (anti‑rust oil, plastic film, wooden crates); full Material Test Report (MTR) provided prior to shipment. |
Contact us to learn about our Inconel 625 production process
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Frequently Asked Questions
Q1: What’s the core difference between Monel 400 and Monel K-500?
A: Monel 400 is solid-solution strengthened, easy to weld, low cost, suitable for static low-load corrosion equipment; Monel K-500 add Al & Ti, precipitation hardening after heat treatment, 2x higher strength, for rotating high-load parts, but easier to generate stress corrosion cracking under strong acid high-temperature environment, welding needs post-weld aging recovery strength. Both own identical seawater corrosion resistance.
Q2: Is Monel 400 magnetic?
A: Monel 400 Curie temperature 21~49℃, partial weak magnetism at room temperature, not suitable for strict non-magnetic working condition; choose Monel K-500 / 404 for zero magnetic permeability demand.
Q3: What’s the corrosion resistance advantage vs 316L stainless steel?
A: Monel alloy is dominant in reducing medium (HF, dilute sulfuric acid, brine), corrosion rate 10~100 times lower than 316L; stainless steel performs better in oxidizing nitric acid environment.
Q4: What’s your MOQ & lead time?
A: Spot standard size MOQ 5kg for sample test; bulk order ≥1 ton. Standard stock goods delivery within 7~15 working days; custom heat treatment & special processing 20~35 days.
Q5: Can you provide full set tender documents & MTR certificate?
A: Yes, every batch supports EN10204 3.1 certificate, SGS/BV third-party inspection report, commercial invoice, packing list, CO form A/E, factory qualification documents for bidding.
Q6: What’s your annual inventory & supply capacity for large projects?
A: 200,000 tons permanent Monel stock, annual export capacity 80,000 tons, accept one-time order over 5000 tons for offshore & refinery EPC projects.
Q7: What welding methods are suitable for Monel alloy?
A: GTAW (TIG), SMAW, GMAW, submerged arc welding recommended; Monel K-500 welding needs post-weld aging heat treatment to restore full mechanical strength.
Q8: Is Monel hard to machine?
A: Monel 400 work hardens rapidly during cutting, need low cutting speed & hard alloy cutter; Monel 405 high sulfur free-machining grade optimized for automatic lathe mass production, processing efficiency improved 40%.
Q9: Why choose Monel instead of duplex stainless steel for seawater pipeline?
A: Long-term seawater service, Monel pitting & crevice corrosion risk far lower than duplex steel, equipment maintenance cycle extended 8~12 years, lower overall life-cycle cost despite higher raw material unit price.
Q10: What industry must use Monel alloy?
A: Hydrofluoric acid alkylation refinery units, deep sea subsea pump shaft, sour gas oilfield downhole tools, desalination evaporator tube, low-permeability electronic sealing components, no alternative economical alloy for above working conditions.