KD Fasteners, Inc.® supplies and manufactures Monel fasteners for equipment that has to survive seawater, acids, and temperature swings that sideline standard alloys. When corrosion resistance and strength both need to hold up in the same fastener, Monel nuts, bolts, washers, and studs deliver where nickel and stainless steel alone fall short.
Why Choose Monel Fasteners?
Monel is a nickel-copper alloy, typically 63% to 70% nickel with copper making up most of the remainder, along with small amounts of iron, manganese, carbon, and silicon. That composition gives Monel higher strength than pure nickel while holding onto excellent resistance to corrosion from seawater, hydrofluoric acid, and a wide range of alkalis, salts, and reducing acids.
Monel fasteners are also largely non-magnetic and keep their mechanical properties across a wide temperature range, from sub-zero conditions up through roughly 1,000°F. That mix of strength, corrosion resistance, and temperature stability is why Monel is specified in marine, oil and gas, and chemical processing equipment where stainless steel alloys would pit or lose strength.
Monel Grades We Carry
KD Fasteners, Inc.® supplies the following Monel grades:
- Monel 400: The standard grade, offering general-purpose corrosion resistance in seawater and industrial atmospheres. The most widely used grade for valves, pumps, and marine equipment.
- Monel 405: A free-machining version of Monel 400 with added sulfur for improved machinability, well-suited to machined fastener components.
- Monel K-500: An age-hardenable grade with aluminum and titanium added for roughly two to three times the strength of Monel 400, while keeping its corrosion resistance. K-500 is the preferred grade for structural fasteners, springs, and shafts that need extra strength.
- Monel 200: Essentially commercially pure nickel, grouped with the Monel family and specified for caustic environments and applications with the highest purity requirements.
Chemical Composition, %
|
Grade |
C |
Mn |
S |
SI |
Ni |
Cu |
Fe |
Al |
Ti |
|
400 |
0.30 max |
2.00 max |
0.024 max |
0.50 max |
63.0 min |
28.0-34.0 |
2.50 max |
- |
- |
|
K-500 |
.25 max |
1.5 max |
0.01 max |
0.50 max |
63.0-70.0 |
Remainder |
2.0 max |
2.30-3.15 |
0.35-0.85 |
Common Monel Applications
Because Monel resists both seawater and aggressive acids, it shows up in some of the most corrosive service conditions across industry, including:
- Marine hardware, propeller shafts, and shipbuilding
- Oil and gas equipment, including hydrofluoric acid alkylation units
- Chemical processing and piping systems
- Aerospace components exposed to corrosive fluids
- Pump, valve, and pressure vessel assemblies
Standard, Metric, and Custom Monel Options
Because Monel is a difficult material to machine and thread, our stock catalog is limited to hex nuts, hex bolts, washers, and studs, produced in the grade you specify. As a metric nuts and bolts supplier, we can produce Monel fasteners to metric sizing alongside standard inch dimensions.
If your application requires a configuration outside our standard offering, KD Fasteners, Inc.® can manufacture Monel fasteners to print.
Request a Quote for Monel Fasteners, Nuts & Bolts Today
Send us your grade, size, and quantity, and our team will help you specify the right Monel fastener for your application. Submit a request for a quote today, and a KD Fasteners specialist will follow up with pricing and availability.
Frequently Asked Questions About Monel Fasteners
What makes Monel different from stainless steel fasteners?
Monel's nickel-copper composition gives it superior resistance to hydrofluoric acid, seawater, and reducing acids that will pit or corrode stainless steel over time. Unlike stainless, Monel doesn't rely on a chromium oxide layer to stay corrosion-resistant, so it holds up in reducing environments where that passive layer can break down.
Are Monel fasteners magnetic?
No. Monel is virtually non-magnetic across our standard grades, thanks to its nickel-copper composition. That makes it a good fit for magnetic-sensitive equipment, subsea instrumentation, and other environments where magnetic interference has to be avoided.
Can Monel fasteners handle high-temperature applications?
Yes. Monel keeps good strength and ductility from sub-zero temperatures up through roughly 1,000°F, and it resists oxidation better than plain nickel across that range. For sustained service above that threshold, our Hastelloy and Inconel alloys are usually a better fit.