Hastelloy Fasteners vs Monel Fasteners – What’s the Difference

Choosing the right type of fastener for an application is crucial to ensure that the final product is of high quality. A fastener connects two or more objects together and can determine if the assembly remains secure and stable over time or if it will fail under load. Regarding fasteners, many different materials, types, coatings and sizes are available – each with its own benefits and drawbacks. In this blog post, we will explore the differences between Hastelloy and Monel fasteners specifically so that you can choose the best option for your project.

What is Hastelloy Fasteners and Monel Fasteners?

Hastelloy fasteners and Monel fasteners are both metals used in various industrial applications. While both are highly corrosion resistant, Hastelloy provides superior protection against localized environments with temperatures greater than 500 degrees Celsius while Monel has better resistance to acids, saltwater, and seawater. Furthermore, Hastelloy is more difficult to work with due to its higher strength, whereas Monel is easier to machine. Both materials offer excellent performance in many different applications.

Hastelloy and Monel fasteners are both made from nickel-based alloys. Hastelloy is an alloy of nickel, chromium, and molybdenum, while Monel is an alloy of nickel and copper. Both alloys are known for their high strength and resistance to corrosion.

Hastelloy and Monel are two popular high-performance alloys frequently used in fasteners. They share many similarities but also differ in some important ways. Here are some of the factors that can help you to differentiate between the two:

Difference Between Hastelloy Fasteners vs Monel Fasteners

1) Composition:

Hastelloy is a family of nickel-based corrosion-resistant alloys containing chromium, molybdenum, tungsten and cobalt. These alloys are designed to offer excellent strength in high-temperature and high-stress environments and resistance to a wide range of corrosive chemicals. On the other hand, Monel is a group of nickel-copper alloys containing iron, manganese, and trace amounts of other elements. These alloys are known for their strength, corrosion resistance, and durability, especially in marine environments.

2) Usage:

Hastelloy fasteners are generally used in applications that require high-temperature resistance, highly corrosive environments, and high strength. Examples include chemical processing, pressure vessels, reactors, valves, and heat exchangers. In contrast, Monel fasteners are often used in marine, oil and gas, aerospace, and other applications where corrosion resistance is critical. They are suitable for use in seawater, brine, salt spray, and other harsh environments.

3) Availability:

Hastelloy fasteners are typically more expensive and less commonly available than Monel fasteners. This is due to their advanced chemical composition and production methods involving complex alloying and processing techniques. Conversely, Monel is more widely available and often more cost-effective, especially for low to medium-stress applications.

4) Machinability:

Both Hastelloy and Monel alloys are known for their toughness, which can make them challenging to machine. However, Hastelloy is generally considered to be more difficult to machine than Monel due to its high hardness and toughness. This can make Hastelloy fasteners more expensive to produce and require more specialized equipment and skills.

5) Corrosion Resistance:

 Hastelloy alloys can resist many highly corrosive chemicals and environments, including acids, chlorides, sulfides, and other aggressive substances. Both Hastelloy and Monel fasteners offer excellent corrosion resistance. Due to their copper content, monel alloys are also highly resistant to corrosion, particularly in seawater and other marine applications. However, Monel may perform better in highly acidic or alkaline environments. However, Monel fasteners are more corrosion-resistant in saltwater environments than Hastelloy fasteners. This is due to the addition of copper to the alloy, which provides better protection against saltwater corrosion.

6) Strength and Durability:

Hastelloy fasteners are stronger and more durable than Monel fasteners. This is due to the higher chromium concentration in Hastelloy, which gives it better wear resistance. Additionally, Hastelloy is less likely to suffer from stress corrosion cracking than Monel.

7) Temperature Resistance:

Hastelloy fasteners can withstand higher temperatures than Monel fasteners. This is due to the higher melting point of Hastelloy, which allows it to withstand temperatures up to 1900 degrees Fahrenheit without deforming. Additionally, Hastelloy is less likely to suffer from thermal shock than Monel.

8) Cost:

Hastelloy fasteners are more expensive than Monel fasteners. This is due to the higher cost of the metals used to make Hastelloy and the fact that it is a more difficult alloy to produce.

Hastelloy and Monel are two alloys that manufacture fasteners for various industrial applications. In terms of cost, Hastelloy tends to be more expensive than Monel. This is mainly because Hastelloy is much more corrosion-resistant than Monel, making it suitable for applications in highly corrosive environments. However, when comparing the cost per application on a case-by-case basis, each alloy may vary in price depending on factors such as size and quantity required.


In conclusion, both Hastelloy and Monel alloys offer excellent strength and corrosion resistance for various applications. Choosing between the two depends on your specific requirements, such as chemical exposure, temperature range, and operating conditions. While Hastelloy fasteners are generally preferred for high-stress and high-temperature applications, Monel fasteners are often a more cost-effective choice for lower-stress applications. Ultimately, consulting with an expert in materials selection and assembly is important to determine which option is best for your project.

Hastelloy Fasteners vs Monel Fasteners – What’s the Difference

by AB Steel time to read: 3 min