817M40 Steel (EN24)

817M40 is a low-alloy steel commonly used for applications requiring high tensile strength, toughness, and fatigue resistance.

It is also known as EN24, AISI 4340, or 34CrNiMo6. The composition of 817M40 steel typically includes carbon, chromium, nickel, molybdenum, and manganese.

  • High strength
  • Fatigue-resistant material
  • Versatile
  • Heat treatable
Aerospace Grade:

817M40 is a British aerospace-grade steel commonly used in the aerospace industry for high-strength applications. It is classified as a low-alloy steel. It is often called an 'aerospace-grade' steel due to its high-performance characteristics and ability to withstand demanding environments. This grade is also used in other industries, such as motorsports and oil and gas, where high strength and toughness are required.

Chemical Composition (weight, %)
* Properties as per BS 970
817M40 (EN24) alloy steel
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817M40 PDF

The steel has excellent fatigue resistance, which means it can withstand cyclic loading without failing. The fatigue resistance of 817M40 steel is due to its high strength, toughness, and the presence of alloying elements such as nickel and molybdenum. These elements improve the steel's resistance to fatigue by increasing its resistance to crack initiation and propagation.

Heat treatment can further improve the material, such as quenching and tempering. Heat treatment can enhance the steel's microstructure and mechanical properties, increasing its strength, toughness and wear resistance. Coatings such as chromium or tungsten carbide can also be applied to the surface of the steel to further increase its wear resistance.

The steel has good wear resistance, making it suitable for applications involving sliding or abrasive wear and where frequent maintenance or replacement is not desirable.

We stock 817M40 in round and square bars.

We process your steel products using in-house processing

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