Anti-loosening bolt

A complete analysis of the material selection of anti-loosening bolts

In many fields such as machinery manufacturing, construction engineering, transportation, etc., anti-loosening bolts are key parts to ensure the stable operation of equipment and structures. The choice of materials directly affects the performance, service life and working safety of the bolts. Different materials give bolts different characteristics to adapt to various complex working environments and working conditions. Next, we will explore in depth the common material selection of anti-loosening bolts, their characteristics and applicable scenarios.

1. Carbon steel material

Carbon steel is one of the commonly used materials for anti-loosening bolts. It is widely used because of its low cost and good processing performance. Carbon steel is mainly composed of iron and carbon. According to the different carbon content, it can be divided into low carbon steel, medium carbon steel and high carbon steel.

(1)Low carbon steel

The carbon content of low carbon steel is generally below 0.25%. It has good plasticity and toughness and is easy to be cold processed, such as stamping and bending. However, due to its low carbon content, its strength and hardness are relatively low. In the manufacture of anti-loosening bolts, low carbon steel is often used to manufacture bolts that do not require high strength but require good plasticity and welding performance, such as connecting bolts in some home appliances and light mechanical equipment. In order to improve the anti-loosening performance of low carbon steel bolts, anti-loosening devices such as spring washers and nylon locking nuts are usually used in conjunction.

(2) Medium carbon steel

The carbon content of medium carbon steel is between 0.25% and 0.6%, and its comprehensive mechanical properties are good. It has certain strength and hardness, as well as good plasticity and toughness. Through appropriate heat treatment (such as quenching and tempering), the strength and hardness of medium carbon steel can be significantly improved, making it suitable for occasions with medium loads. In the fields of building steel structure and general machinery manufacturing, medium carbon steel anti-loosening bolts are widely used. For example, in the steel structure connection of some industrial plants, medium carbon steel anti-loosening bolts are used in combination with double nuts or thread lockers to effectively prevent the bolts from loosening and ensure the stability of the steel structure.

(3) High carbon steel

The carbon content of high carbon steel is above 0.6%. It has high strength and hardness, but relatively poor plasticity and toughness. High carbon steel anti-loosening bolts usually need to undergo rigorous heat treatment processes to improve their performance to meet specific usage requirements. Due to their high strength characteristics, high carbon steel bolts are often used in the manufacture of occasions that need to withstand large tensile and impact forces, such as connecting parts of heavy machinery, anchor bolts of bridges, etc. However, high carbon steel bolts need to be used to prevent brittle fracture, so they should be used with caution in some scenarios with high toughness requirements.

2. Alloy steel material

Alloy steel is made by adding one or more alloying elements (such as manganese, chromium, molybdenum, vanadium, etc.) to carbon steel. Through alloying and proper heat treatment, alloy steel can obtain better properties than carbon steel, such as higher strength, hardness, wear resistance, corrosion resistance and heat resistance.

1. Low alloy steel

The total content of alloying elements in low alloy steel generally does not exceed 5%. Compared with carbon steel, low alloy steel has significantly improved strength, toughness, corrosion resistance, etc., while maintaining good processing performance. In the manufacture of anti-loosening bolts, low alloy steel is often used in situations where performance requirements are high but costs need to be controlled. For example, in the automotive manufacturing industry, anti-loosening bolts made of low alloy steel are widely used in the connection of key components such as engines and chassis to ensure the safety and reliability of vehicles under various working conditions. In addition, in some outdoor mechanical equipment and building structures, low alloy steel anti-loosening bolts can effectively resist the erosion of bolts by environmental factors due to their good corrosion resistance, thereby extending the service life of the bolts.

2. High alloy steel

The total content of alloying elements in high alloy steel is usually above 10%, and it has special physical, chemical and mechanical properties. Common high alloy steels include stainless steel, heat-resistant steel, etc.

Stainless steel : Stainless steel has excellent corrosion resistance, thanks to a dense chromium oxide protective film formed on its surface, which can effectively prevent steel from chemically reacting with air, water and other media, thereby avoiding rust and corrosion. In the field of anti-loosening bolts, stainless steel is widely used in food processing, medical equipment, chemical industry, marine engineering and other industries with extremely high requirements for corrosion resistance. For example, in food processing plants, stainless steel anti-loosening bolts will not pollute food, and can maintain good performance in humid environments with acid and alkali steam; in marine engineering, stainless steel anti-loosening bolts can resist the corrosion of seawater and ensure the connection stability of equipment such as offshore platforms and ships. According to the different organizational structures of stainless steel, it can be divided into austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, etc. Different types of stainless steel have their own characteristics in performance and application.

Heat-resistant steel : Heat-resistant steel has good high-temperature strength and oxidation resistance, and can work for a long time in high-temperature environment without deformation and damage. In the power, metallurgy, petrochemical and other industries, many equipment need to operate under high-temperature conditions, such as boilers, heating furnaces, steam turbines, etc., and a large number of anti-loosening bolts made of heat-resistant steel are used in these equipment. Heat-resistant steel bolts can maintain high strength and hardness at high temperatures through special alloy composition design and heat treatment process, prevent bolts from loosening and failure in high-temperature environment, and ensure safe and stable operation of equipment.

3. Non-ferrous metal materials

In addition to carbon steel and alloy steel, some non-ferrous metals and their alloys can also be used to manufacture anti-loosening bolts. These materials usually have unique performance advantages and are suitable for specific application scenarios.

1. Aluminum alloy

Aluminum alloy has the characteristics of low density and light weight, and also has certain strength and good corrosion resistance. Aluminum alloy anti-loosening bolts have been widely used in aerospace, automobile lightweighting and other fields. In the aerospace field, reducing the weight of the aircraft is crucial to improving flight performance and fuel efficiency. Aluminum alloy anti-loosening bolts can effectively reduce the overall weight of the aircraft due to their lightweight characteristics; in automobile manufacturing, with the continuous improvement of automobile fuel economy and environmental protection performance requirements, automobile lightweighting has become a development trend. The application of aluminum alloy anti-loosening bolts in automobile engines, chassis and other parts helps to reduce the weight of the car and improve fuel efficiency. In addition, the surface of aluminum alloy can be further improved through anodizing and other treatment processes to improve its corrosion resistance and aesthetics.

2.Copper alloy

Copper alloys have good electrical conductivity, thermal conductivity and corrosion resistance. In the fields of electrical equipment, electronic instruments, etc., copper alloy anti-loosening bolts have unique application value. For example, in electrical equipment such as power transformers and distribution cabinets, copper alloy anti-loosening bolts are used to connect electrical components. Their good electrical conductivity can ensure the reliability of electrical connections and reduce contact resistance. At the same time, the corrosion resistance of copper alloys can ensure that the bolts will not rust in a humid electrical environment and affect electrical performance. Common copper alloys include brass, bronze, etc. Different types of copper alloys have different performances and can be selected according to specific usage requirements.

The material selection of anti-loosening bolts is a process that comprehensively considers multiple factors. It is necessary to select the appropriate material based on the actual working environment, load requirements, cost budget, etc. With the continuous development of material science and manufacturing technology, more new materials with excellent performance will be applied to the field of anti-loosening bolt manufacturing in the future, providing more reliable connection guarantees for the development of various industries.