Monel 400 bolts are high-performance fasteners made from a nickel-copper alloy, renowned for their exceptional strength, excellent corrosion resistance, and outstanding performance in severe environments. These bolts are commonly used in industries such as marine, chemical processing, and power generation, where harsh conditions such as high-temperature environments and exposure to seawater are prevalent. Monel 400 bolts are ideal for applications that require reliable mechanical strength, resistance to corrosion, and long-lasting durability.
MWalloys is a metal-materials specialist based in China, devoted to advanced alloy fasteners such as Monel 400 bolts, studs, nuts, and washers. We manufacture entirely in-house, controlling quality via certified mills, forging, machining and QC inspection—leading to consistent properties and product traceability.
Whay choose MWalloys?
Our product line & manufacturing control
We offer standard and custom Monel 400 fasteners: hex bolts, socket cap screws, carriage bolts, studs, flange bolts, threaded rod, washers and nuts. All products meet UNS N04400, ASTM F468/F467, ASME SB-468/SB-467, DIN 2.4360, BS NA13 standards. We supply metric (M2–M160) and inch sizes, various coarse/fine threads, finishes, fully or half threaded options.
Factory direct pricing & fast lead times
As a 100% factory supplier, MWalloys provides factory-gate pricing—no distributors, no middle margins—plus ample stock for urgent requirements. Standard stock delivery: shipped within 7–14 business days; large orders or custom specifications: 15–30 days max. We combine speed with full material test certificates (EN 10204/3.1B) and packing documentation.
What Are Monel 400 Bolts?
Monel 400 bolts are fasteners made from Monel 400 alloy, which is composed primarily of nickel and copper, with small amounts of iron, manganese, carbon, and silicon. Monel 400 is a solid-solution alloy that is resistant to a wide range of corrosive environments, including seawater, sulfuric and hydrochloric acids, and many others. These bolts are designed to provide strength, toughness, and resistance to both corrosion and oxidation, making them suitable for high-performance applications.
Bolt types & Standards
Applications include:
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Hex bolts, heavy hex bolts, carriage bolts
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Stud bolts, full-thread studs, double-end, tap end
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Socket head cap screws, washers, flange bolts
Standards: ASTM F468 for bolts & screws, ASTM F467 for nuts, DIN EN 2.4360, BS NA13, UNS N04400 etc.
Usefulness: widely used in marine, chemical processing, offshore oil & gas, petrochemical, nuclear, and high-temperature equipment.
Material Properties & Mechanical Data
| Temperature (°C / °F) | Tensile Strength | Yield Strength (0.2% offset) | Elongation % |
|---|---|---|---|
| –196 °C (liquid N₂) | ~620 MPa (90 ksi) | ~345 MPa (50 ksi) | ~60% |
| 20 °C (room temp) | ~620 MPa (90 ksi) | ~345 MPa (50 ksi) | ~60% |
| 200 °C (392 °F) | ~610 MPa (88 ksi) | ~340 MPa (49 ksi) | 55–60% |
| 400 °C (752 °F) | ~600 MPa (87 ksi) | ~330 MPa (48 ksi) | 50–55% |
| 500 °C (932 °F) | ~550 MPa (80 ksi) | ~300 MPa (43 ksi) | ~50% |
These values highlight Monel 400’s ability to maintain strength and ductility across wide temperature ranges. It does not undergo a brittle-transition at cryogenic levels, unlike ferrous alloys.
Additional mechanical property: Modulus of elasticity ~179 GPa (26 000 ksi); density ~8.8 g/cm³; melting range 1 300–1 350 °C (2 370–2 460 °F).
Chemical Composition Table
| Element | Min % | Max % |
|---|---|---|
| Nickel (Ni) | 63.00 | — |
| Copper (Cu) | 28.00 | 34.00 |
| Iron (Fe) | — | 2.50 |
| Manganese (Mn) | — | 2.00 |
| Silicon (Si) | — | 0.50 |
| Carbon (C) | — | 0.30 |
| Sulfur (S) | — | 0.024 |
This composition ensures resistance to corrosion in cutting environments—from seawater to hydrofluoric acid and diluted sulfuric/hydrochloric acids under reducing conditions.
Equivalent Grades & Specification Cross-References
Monel 400 (UNS N04400, DIN 2.4360, BS NA13, ASTM B164, B127, F468/F467) is standard. Closely related alloys or equivalents:
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Monel K-500 (UNS N05500, DIN 2.4375, ASTM B865): precipitation hardened, ~2× strength, even better corrosion resistance, but stronger and less ductile.
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European: NiCu30Fe standard grades cover equivalent chemistry.
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Indian: BS 3076 NA13.
These equivalents allow engineers to cross-spec Monel 400 when designing joint materials.
Sizes, Threads, Weights & Standards
Size range: commonly stocked from M2 to M160 (metric), and #2 to 1-1/2″ or 1-3/4″ in imperial format. Lengths range from 3 mm up to 200 mm or extended lengths by request.
Thread types: UNC, UNF, UN, BSF, BSW, ISO metric.
Weight estimation: depending on bolt diameter and length, for example:
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A ½″-13 × 2″ hex bolt weighs approximately ~0.1 lb (45 g).
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A M12 × 50 mm hex bolt weighs around ~20–25 g.
(full charts may reference engineering tables).
Standards include ASTM F468 (bolts), F467 (nuts), ASME SB-468/F-467, DIN EN 2.4360, BS 3076 NA13.
Global Price Comparison 2025
| Region | Typical Price per ½″-13 × 2″ Hex Bolt (USD) | Notes |
|---|---|---|
| USA (import) | USD 9–12 | Includes shipping, small-quantity premium |
| Europe (import) | EUR 8–10 (≈ USD 9–11) | Similar to US pricing structure |
| China (factory) | USD 6–8 | Factory direct price, high volume discount |
| MWalloys China | USD 6.50 | Factory-gate, includes inspection certificates, bulk and small orders priced same |
Exchange rates and shipping vary, but MWalloys positions pricing about 20–30% lower than import-sourced pricing, with no middle margins and fast delivery from China stock.
Applications & Typical Industry Use Cases
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Marine and Offshore: seawater pumps, valve bodies, propeller shafts, hull fixtures – exceptional resistance to rapid moving saltwater and preventing stress corrosion cracking.
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Chemical Processing: pipelines and fasteners in concentrated HF, Hâ‚‚SOâ‚„ under reducing conditions, caustic lines, chemical reactors.
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Oil & Gas / Petrochemical: offshore platforms, heat exchangers, separators, scrubber systems where high strength and corrosion resistance are needed.
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Cryogenic Applications: liquid hydrogen equipment, subzero valves, storage vessels—Monel 400 remains ductile at cryogenic temperatures.
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High-temperature service: up to ~1 000 °F (538 °C) in oxidizing or reducing atmospheres.
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Nuclear & Power Generation: fasteners in steam generators, chemical injection systems.
Frequently Asked Questions (FAQs)
1. Can Monel 400 bolts be heat treated to increase strength?
No, Monel 400 is a solid-solution alloy. It cannot be precipitation-hardened; only cold working can influence hardness slightly.
2. How does Monel 400 compare with Monel K-500?
Monel K-500 offers higher strength due to aging hardening, but Monel 400 retains more toughness and ductility, especially at cryogenic temperatures. Cost is lower too.
3. Is Monel 400 magnetic?
No, Monel 400 is non-magnetic at room temperature and remains so in most service environments.
4. Can MWalloys supply metric custom lengths or threads?
Yes. We support fully custom lengths, fine/coarse or specialty threads, and special finishes as requested with competitive MOQ.
5. Are Monel 400 bolts weldable or machinable?
Yes, excellent machinability and weldability using standard techniques; can be brazed or TIG-welded when required.
6. How long is the typical service life of Monel 400 bolts?
Often 25–35 years in marine or chemical environments when properly installed and insulated against galvanic corrosion.
7. Does Monel 400 resist hydrofluoric acid?
Yes, excellent resistance to hydrofluoric acid in all concentrations up to boiling, and good resistance to sulfuric and hydrochloric under reducing conditions.
8. What documentation comes with MWalloys’ Monel 400 bolts?
Complete EN 10204/3.1B material certificates, dimensional reports, thread gauge verification, visual & magnetic particle inspections as needed.
9. Are there any situations Monel 400 should not be used?
It is not suitable in strong oxidizing acids (e.g. hot nitric acid) or in highly acidic, aerated sulfuric acid above certain concentrations; consult corrosion charts.
10. Is there minimum order quantity?
We accept both single-piece trial orders via stock and larger bulk orders, with same factory direct price bracket.
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