21CrMoV5-7, 1.7709 Steel for fasteners

September 16, 2023 | Tags: 21CrMoV5-7, 1.7709,

September 16,2023

21CrMoV5-7, 1.7709 Steel for fasteners

Title: 21CrMoV5-7 Steel: The Optimal Choice for Fasteners


Fasteners play a critical role in various industrial applications, ensuring the stability and reliability of structures and machinery. In recent years, 21CrMoV5-7 steel has emerged as a highly sought-after material for fasteners due to its exceptional properties and outstanding performance. This article aims to explore the unique characteristics of 21CrMoV5-7 steel and highlight its suitability as a top choice for fastener applications.

Composition and Properties:

21CrMoV5-7 steel belongs to the family of chromium-molybdenum-vanadium steels, renowned for their exceptional strength and toughness. The chemical composition of 21CrMoV5-7 steel consists of 0.17-0.25% carbon, 0.40-1.00% manganese, 0.70-1.20% chromium, 0.60-0.95% molybdenum, 0.10-0.30% vanadium, and small amounts of other trace elements. 

The unique combination of alloying elements contributes to the remarkable mechanical properties of 21CrMoV5-7 steel. With a minimum yield strength of 800 MPa and an ultimate tensile strength ranging from 980 to 1180 MPa, this steel exhibits excellent resistance to deformation and can withstand high-stress environments. Furthermore, its high hardenability and superior impact toughness make it suitable for critical applications requiring resistance to various dynamic loads.

Corrosion Resistance:

In addition to its exceptional mechanical properties, 21CrMoV5-7 steel demonstrates remarkable corrosion resistance. The chromium content in the alloy provides excellent protection against oxidation and corrosion, ensuring the longevity and durability of fasteners. This resistance to atmospheric and chemical corrosion significantly enhances the reliability and safety of structures and machinery in various industries.

Heat Treatment and Machinability:

21CrMoV5-7 steel can be heat-treated to optimize its mechanical properties and achieve the desired hardness levels. A common heat treatment method involves quenching and tempering to enhance the material's toughness and strength. With the right heat treatment procedures, manufacturers can tailor the mechanical properties of 21CrMoV5-7 steel to meet specific application requirements.

Furthermore, this steel exhibits good machinability, allowing for ease of fabrication and processing. The combination of its excellent machinability and heat treatability makes 21CrMoV5-7 steel an ideal material for manufacturing precision fasteners with intricate designs.


The exceptional properties of 21CrMoV5-7 steel make it an indispensable choice for a wide range of fastener applications. These include, but are not limited to:

- Automotive industry: Critical components such as engine parts, transmission systems, and suspension systems.

- Aerospace industry: Fasteners used in aircraft engines, landing gears, and structural components.

- Energy sector: Fasteners for power generation systems, including wind turbines, nuclear reactors, and thermal power plants.

- Manufacturing and construction industry: Fasteners for heavy machinery, construction equipment, and infrastructure projects.


21CrMoV5-7 steel is a superior choice for fastener applications, offering exceptional mechanical properties, corrosion resistance, heat treatability, and machinability. Its versatility and reliability make it a top preference for various industries, ensuring the stability, longevity, and safety of structures and machinery. By choosing 21CrMoV5-7 steel for fasteners, manufacturers can achieve optimal performance and satisfaction for their customers.

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