Product Overview: Monel Alloy 400

An In-Depth Overview of its Chemical Composition, Properties and Applications

Monel alloy 400 is a high strength, corrosion resistant nickel alloy. It is incredibly versatile with a range of applications, including the marine and chemical processing industry. We’ll take a look at the properties, applications and chemical composition that make Monel 400 unique.

What is Monel 400?

Monel 400, also known as Alloy 400, is a nickel alloy supplied by NeoNickel. It has a high percentage of copper, which makes it so corrosion resistant.

Chemical Composition

An alloy is made by combining a metal with one or more alloying elements to give it enhanced properties. Monel 400 is a nickel-copper alloy, featuring more copper than other nickel alloys.


Nickel is the base metal of Monel 400, meaning it makes up the majority of its composition. Indeed, it makes up 63-70%. This high percentage of nickel also makes it resistant to chloride-induced stress corrosion cracking.


Copper is the second largest element and makes up 28-34% of its chemical composition. Copper is a highly corrosion resistant metal, so enhances the corrosion resistance of Monel 400.


Iron makes up between 0-2.5% of Monel 400, and contributes to its mechanical strength and overall stability.

Other Elements

Alloy 400 contains trace amounts of other elements including manganese (0-2%), silicon (0-0.5%), carbon (0-0.3%) and sulphur (0-0.024%).

Properties of Monel 400

Corrosion Resistant

Monel 400 demonstrates excellent corrosion resistance to a range of media, including seawater, hydroflouric acid, fluorine, sulphuric acid and alkalis. In fact, it is one of only a few alloys that can be used with hydrofluoric acid and fluorine. Its high nickel content also makes it immune to chloride-induced stress corrosion cracking.

High Strength

Alloy 400 is also high strength, even at extreme temperatures. It maintains its structural integrity, making it suitable for high stress or pressure applications. From sub-zero temperatures to 549°C, you can count on it to maintain good mechanical properties.

Good Ductility

Monel 400 has good ductility, which allows it to be shaped into various forms. Here at NeoNickel, Alloy 400 is available as round bar, round tubing, pipe, pipe fittings, flanges, sheet and plate. The ability to buy Alloy 400 in so many forms means it can be used for almost anything.

Low Cost

Monel 400 is a great low cost alternative to some of the pricier nickel alloys, whilst offering similar properties and performance.

Applications of Monel 400

Chemical Processing

Monel 400 is resistant to a range of chemicals, including hydroflouric acid, fluorine, sulphuric acid and alkalis. It is therefore often the alloy of choice in the chemical processing industry. It is used in pumps, pipes, valves and pressure vessels. It is a cost effective option for this industry, which means they won’t have to replace parts as often due to corrosion.

Oil and Gas

Like the chemical processing industry, the oil and gas industry deal with a range of corrosive substances. Monel 400 is one of the few alloys that can handle this. It can also handle harsh seawater conditions, so it is often used in subwater applications.

Marine Engineering

Seawater can corrode most metals quickly, like iron or stainless steel. Because of its corrosion resistance to seawater, Alloy 400 is often used in marine engineering.That can include use on submarines, underwater pipes and valves.


Monel 400 can also be used in the aerospace industry, although this is less common. This is because of its ability to withstand extreme temperatures, from the subzero to 500°C+. It is often used in aircraft fuel tanks, exhaust systems and landing gear components.

Monel 400 is a low cost, corrosion resistant nickel alloy. It is often the alloy of choice for the chemical processing industry and subsea applications, due to its exceptional corrosion resistance. It can be used in places that other alloys simply cannot.

Visit our Alloy 400 product page to find out more about this useful alloy. There, you can find a full breakdown of its chemical composition and properties, including tensile strength, thermal expansion and thermal conduction. If you need any help understanding this data and its properties, please get in touch at

If Alloy 400 sounds like the alloy for you, please fill out our enquiry form. It is suitable for a range of industries, including the chemical processing, marine and oil and gas industries.

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