In the repair and maintenance of construction machinery, it is crucial to choose suitable bolts and nuts. In this article, we will discuss the relevant knowledge of bolts and nuts of excavators and bulldozers from the perspective of selection and application to provide reference for professionals.

1. Selection of bolts

1. Choose according to mechanical components: Different mechanical components have different requirements for bolts. For example, track plate bolts need to withstand greater impact and abrasion, and therefore need to choose higher strength bolts, while the supporting wheel bolts pay more attention to its anti-fatigue properties.
2. Strength level and material: Choose the appropriate strength level and material of bolts according to the requirements of working conditions. Although the price of high-strength bolts is higher, they can effectively improve the safety and service life of machinery.
3. Thread type: The selection of metric and imperial bolts should be determined according to the mechanical design and availability of accessories. When replacing bolts, make sure that the new bolt matches the thread type of the old bolt.

2. Nut selection

1. Matching Bolts: The nut should match the bolt to ensure a tight fit and reliable connection
2. Strength Grade: Similar to bolts, nuts need to be of the appropriate strength grade for the application. High-strength nuts can provide better tightening effect and loosening resistance.
3. Anti-corrosion and Wear Resistance: In harsh working conditions, such as wet, dusty or corrosive environments, the anti-corrosion and wear resistance of the nut id particularly important. Select the nut with anti-corrosion coating or stainless steel material can effectively extend its service life and reduce the loosening or fracture caused by corrosion.

3. Installation and inspection of bolts and nuts

1. Preparation before installation

• Clean the oil, rust and other impurities in the installation area of the bolt and nut to ensure that the installation surface is clean and smooth
• Check whether the specification, material and strength level of the bolts and nuts meet the requirements, and avoid mixing products of different batches or manufactures.

2. Installation steps

• Tighten the bolts and nuts according to the specified torque and sequence to avoid over-tightening or over-loosening
• Use appropriate tools, such as torque wrenches, to ensure the accuracy and consistency of the tightening torque.
• During installation, pay attention to the perpendicularity of the bolts and nuts to avoid skewing or misalignment.

3. Checking after installation

• Check the tightening statues of bolts and nuts to ensure that there is no looseness or abnormal phenomena.
• Conduct the necessary torque review to verify that the tightening torque meets the requirements.
• Observe the surface condition of the bolts and nuts and check for damage or cracks.

4. Maintenance and care of bolts and nuts

1. Periodic inspection: Regularly inspect the bolts and nuts in construction machinery, and promptly find and deal with loosening, wear and corrosion,etc.
2. Replacement and repair: For serious wear, corrosion or damage to the bolts and nuts, should be replaced in a timely manner. In the replacement process, pay attention to the selection and the original parts of the same specifications, materials and strength level of the new parts. At the same time, for repaired using appropriate methods.
3. Storage and maintenance: Store the unused bolts and nuts in a dry, ventilated, non-corrosive gas environment to avoid moisture or contamination. At the same time. Regularly inspect and maintain the stored bolts and nuts to ensure that they are in good working condition.

5. Caution

• When replacing bolts and nuts, always follow the machine manufacturer’s recommendations and instructions.
• Avoid tightening bolts and nuts with unsuitable tools or methods to avoid damaging the threads and jeopardizing the tightening effect.
• In severe working conditions, monitor and maintain the bolts and nuts to ensure they are always in good working condition.

Bolts and nuts in excavators and bulldozers are important components to ensure the safety and performance of the machinery. By choosing the right bolts and nuts, proper installation and inspection, regular maintenance and repair, we can effectively extend the service life of these parts and improve the reliability of the project. HOK is committed to be your preferred brand of construction machinery parts to protect your equipment.