Materials Highlight: Monel

Monel is a group of nickel alloys primarily composed of nickel (up to 67%) and copper, with small amounts of iron, manganese, carbon and silicon. The combination of elements is stronger than pure nickel and a registered trademark of the Special Metals Corporation. Monel is resistant to corrosion by many agents, specifically rapidly flowing seawater. It can be fabricated readily by hot and cold working, machining and welding.

What are the characteristics of Monel?

In addition to corrosion resistance, it’s well-known as a strong, rust-fighting material. It’s a solid solution binary alloy and is very difficult to machine as it work-hardens quickly. It needs to be turned and worked at slow speeds and low feed rates. Some alloys can withstand a fire in pure oxygen.

Common Industry Applications of Monel

Common applications include the aerospace industry, oil production and refining, musical instruments (trumpets, tubas and French horns), and marine applications. Monel’s corrosion resistance makes it perfect for piping systems, pump shafts, seawater valves and strainer baskets in seawater environments. The one downside to Monel: it’s not cheap. It’s an expensive alloy that costs 5-10 times more than copper and nickel and three times more than carbon steel.

Its combination of corrosion strength and above-average weldability makes it an invaluable fastener material. Elgin has a complete list of technical specifications for its four different Monel materials and common applications that they are proven to work the best in. Elgin’s Monel materials are a step up from the competition.

For fasteners, each Monel property has its own specific use and practicality. For example:

Monel 400: a solid-solution alloy that can be hardened only by cold working. It has high strength and toughness over a wide temperature range and excellent resistance to many corrosive environments. It’s a trademark of Special Metal Corporation.

  • Monel 405: a free-machining grade of alloy 400 that has greater sulfur content which enhances machinability. It has a slightly different range of mechanical properties than Monel 400 and is used mainly in automatic screw machine stock.
  • Monel K-500: a nickel-copper alloy which takes Monel 400’s advantages and adds greater strength and hardness by adding aluminum and titanium.
  • Nickel 200: a commercially pure (99.6%) wrought nickel that features magnetic and magnetostrictive properties, high thermal and electrical conductivities, low gas content, and low vapor pressure.

Overall, the picture is clear: if you have a specific fastener need, Elgin’s inventory is large and diverse enough to solve the problem.

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