3900274
Hexagon Head Cap Screw
Cummins®

The Cummins Hexagon Head Cap Screw (Part #3900274) is a critical component used in commercial trucks. It ensures structural integrity and reliable performance in these vehicles. This screw is designed to withstand the demanding conditions encountered in truck operations, providing a secure fastening solution for various applications.

Basic Concepts of Hexagon Head Cap Screws

A Hexagon Head Cap Screw is a fastener characterized by its hexagonal head, which allows for efficient torque application using a wrench or socket. These screws are typically made from materials such as carbon steel, stainless steel, or alloy steel, chosen for their strength and durability. They come in various threading types and sizes to accommodate different fastening needs ¹.

Purpose of the 3900274 Hexagon Head Cap Screw in Truck Operations

This Cummins part serves specific functions in the operation of commercial trucks. It is used in various truck components and systems where secure and durable fastening is required. This includes applications in the engine, transmission, chassis, and other critical areas where vibrations and loads are significant. The screw helps maintain the integrity of these components, ensuring they function correctly and safely.

Key Features of the 3900274 Hexagon Head Cap Screw

Several key features distinguish the 3900274. Its hexagonal head design allows for precise torque application, reducing the risk of cam-out during installation. The screw has a specific thread pitch that ensures a strong and secure hold. Additionally, it may feature special coatings or treatments, such as zinc plating or black oxide coating, to enhance corrosion resistance and durability in harsh operating conditions.

Benefits of Using the 3900274 Hexagon Head Cap Screw

Using this part in truck maintenance and repair offers several advantages. The design of the screw allows for improved torque application, ensuring that fasteners are tightened to the correct specifications. Its resistance to loosening under vibration makes it ideal for truck applications where components are subject to constant movement. Furthermore, the durability of the screw ensures longevity, reducing the need for frequent replacements and maintenance.

Installation and Usage Guidelines

Proper installation of the 3900274 is crucial for ensuring secure fastening. The installation process should begin with selecting the appropriate tool, such as a wrench or socket, that matches the size of the screw’s hexagonal head. The screw should be inserted into the pre-drilled hole, ensuring correct alignment with the mating component. Torque specifications provided by the manufacturer should be followed to achieve the proper tightening force. Using a torque wrench can help ensure accuracy in applying the correct amount of torque.

Troubleshooting and Maintenance

Common issues associated with Hexagon Head Cap Screws include loosening due to vibration, corrosion, and wear. To troubleshoot these issues, regular inspections should be conducted to check for signs of loosening or damage. If a screw appears loose, it should be re-tightened to the specified torque. Corrosion can be addressed by cleaning the screw and applying a protective coating. In cases where the screw is damaged or worn, it should be replaced to maintain the integrity of the fastening.

Cummins: A Brief Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a history spanning over a century, Cummins is committed to providing reliable and innovative solutions for the commercial vehicle industry. The company’s product range includes engines, powertrains, and aftermarket parts, all designed to meet the demanding requirements of commercial applications. Cummins’ commitment to quality and innovation is evident in its components, such as the 3900274, which are engineered to deliver reliable performance in challenging environments.

Cummins Engine Part 3900274: Hexagon Head Cap Screw

The Cummins part number 3900274, a Hexagon Head Cap Screw, is a critical component in the assembly and maintenance of various Cummins engines. This part is integral to the structural integrity and operational efficiency of the engines, ensuring that components are securely fastened and aligned.

Application in Cummins Engines

6C8.3 and C8.3 G Engines

The Hexagon Head Cap Screw (part number 3900274) is utilized in both the 6C8.3 and C8.3 G engines. These engines are part of Cummins’ lineup, known for their reliability and performance in various applications. In these engines, the screw plays a pivotal role in securing various engine components, ensuring that they remain tightly fastened under the operational stresses of the engine.

Common Usage

In both the 6C8.3 and C8.3 G engines, the Hexagon Head Cap Screw is commonly used in the following areas:

• Cylinder Head Assembly: Ensuring the cylinder head is securely fastened to the engine block, preventing leaks and maintaining compression.
• Valve Cover Attachment: Securing the valve cover to the engine, which is crucial for protecting the internal components and maintaining the engine’s air-tight seal.
• Turbocharger Mounting: Fastening the turbocharger to the engine, which is essential for maintaining the turbocharger’s position and ensuring efficient airflow.

Importance of the Screw

The use of a Hexagon Head Cap Screw in these engines is critical for several reasons:

• Durability: The screw is designed to withstand high temperatures and pressures, ensuring longevity and reliability.
• Precision: The hexagonal head allows for precise tightening and alignment, which is essential for maintaining engine performance and efficiency.
• Ease of Use: The design facilitates easy installation and removal, which is crucial during maintenance and repair operations.

By ensuring that components are securely fastened, the Hexagon Head Cap Screw contributes to the overall reliability and performance of the 6C8.3 and C8.3 G engines.

Role of Part 3900274 Hexagon Head Cap Screw in Engine Systems

Part 3900274, a Hexagon Head Cap Screw, is integral to the secure assembly and operation of various engine components. In the context of the alternator, this screw plays a significant role in ensuring the alternator is properly mounted and secured within the engine bay.

Alternator Location and Mounting

The alternator is a vital component responsible for generating electrical power to charge the battery and power the vehicle’s electrical systems while the engine is running. Proper mounting of the alternator is essential for its efficient operation and longevity.

Part 3900274 Hexagon Head Cap Screw is used to fasten the alternator to its designated location on the engine block or mounting bracket. This secure attachment ensures that the alternator remains stable and aligned correctly with the engine’s accessory drive belt. The screw’s hexagonal head allows for easy tightening and loosening using a socket wrench, facilitating straightforward installation and maintenance procedures.

By providing a robust connection, Part 3900274 helps prevent vibrations that could otherwise lead to loosening over time, which might result in inefficient belt tension or even detachment. This, in turn, ensures consistent performance of the alternator and reliable electrical supply to the vehicle’s systems.

Conclusion

The Cummins Hexagon Head Cap Screw (Part #3900274) is a vital component in the maintenance and operation of commercial trucks and Cummins engines. Its design and features ensure secure fastening, durability, and ease of use, contributing to the overall reliability and performance of the vehicles. Proper installation and maintenance of this part are essential for ensuring the longevity and efficiency of the components it secures.