3900678
Hexagon Flange Head Cap Screw
Cummins®

The Hexagon Flange Head Cap Screw, specifically the Part #3900678 by Cummins, is a component utilized in commercial truck applications. This screw is designed to secure various components within the truck’s structure and systems, ensuring stability and reliability. Its role is significant in maintaining the integrity of truck assemblies, contributing to the overall performance and safety of the vehicle.

Basic Concepts

Hexagon Flange Head Cap Screws are characterized by their hexagonal head and flanged design. The hexagonal head allows for efficient torque application using standard tools, while the flange distributes the clamping force over a larger area, reducing the risk of damage to the fastened material. These screws are typically made from materials such as steel or stainless steel, chosen for their strength and resistance to corrosion. In the automotive industry, they are commonly used to secure engine components, body panels, and other critical parts ¹.

Functionality

The Hexagon Flange Head Cap Screw operates by threading into a pre-drilled hole, creating a secure connection between two or more components. The screw’s mechanism involves the interaction between the threads and the material, generating friction that holds the components in place. The flanged head plays a role in distributing the clamping force, which helps prevent the screw from pulling through the material and reduces the likelihood of damage to the fastened components.

Role in Truck Operation

Within the context of a truck’s structure and systems, the 3900678 Hexagon Flange Head Cap Screw serves specific purposes. It is used in various applications, including securing engine components, attaching body panels, and fastening other critical parts. Its design and material properties make it suitable for withstanding the rigors of truck operation, ensuring that components remain securely fastened under varying conditions.

Key Features

The 3900678 Hexagon Flange Head Cap Screw features a hexagonal head that allows for easy and efficient torque application. The flange provides a larger surface area for distributing the clamping force, enhancing the security of the fastened components. Additionally, the screw is made from high-quality materials that offer resistance to corrosion and wear, contributing to its durability and performance in demanding environments.

Benefits

Using the 3900678 Hexagon Flange Head Cap Screw offers several advantages. The design of the screw enhances the security of fastened components, providing a reliable connection that can withstand vibration and movement. The flanged head contributes to ease of installation and removal, making maintenance and repairs more efficient. Additionally, the material properties of the screw offer resistance to corrosion, ensuring longevity and reliable performance in various operating conditions.

Troubleshooting and Maintenance

Common issues with Hexagon Flange Head Cap Screws may include loosening due to vibration or corrosion. Regular inspection and maintenance can help identify and address these issues before they lead to more significant problems. Recommended practices include checking for signs of corrosion, ensuring proper torque during installation, and replacing screws that show signs of wear or damage. Troubleshooting tips may involve assessing the condition of the fastened components and ensuring that the screw is the correct size and type for the application ².

About Cummins

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a history of innovation and commitment to quality, Cummins has established a reputation for producing reliable and high-performance components for the commercial vehicle industry. The company’s product range includes a variety of engine and component solutions, designed to meet the demanding requirements of commercial truck applications. Cummins’ commitment to quality and innovation is evident in components like the 3900678 Hexagon Flange Head Cap Screw, which is engineered to provide durability, performance, and reliability in truck operations.

Hexagon Flange Head Cap Screw 3900678 in Cummins Engines

The Cummins Hexagon Flange Head Cap Screw part number 3900678 is a critical component in various Cummins engines, providing essential fastening for different parts within the engine assembly. This screw is designed to securely fasten components together, ensuring the engine operates efficiently and reliably.

Engines Utilizing 3900678

• 15N CM2380 M104B: This engine benefits from the precise fastening capabilities of the 3900678 screw, ensuring that critical components remain securely in place under operational stresses.
• 4B3.9 and 6B5.9: Both these engines use the 3900678 screw to maintain the integrity of their respective assemblies, ensuring that parts such as covers and housings are fastened securely.
• 6C8.3 and C8.3 G: These engines rely on the 3900678 screw for fastening various components, ensuring that the engine’s structural integrity is maintained.
• B3.9 G, B4.5 CM2350 B129B, B4.5 RGT, B5.6 CM2670 B152B, B5.9 G, B5.9 GAS PLUS CM556, B6.7 CM2350 B135B, B6.7 CM2670 B153B, B6.7 CM2670 B164C, B6.7 G CMOH6.0 B125, B6.7S, C GAS PLUS CM556: These engines, which share similar design elements, utilize the 3900678 screw for fastening various parts. This screw ensures that components such as covers, housings, and other critical parts are fastened securely, contributing to the engine’s overall performance and longevity.
• D4.0 CM2620 D103B, F2.8 CM2620 F135B, F3.8 CM2350 F120B, F3.8 CM2350 F128C, F3.8 CM2620 F137B, F3.8 F102, F4.5 CM2620 F139B, F4.5 CM2620 F141C: These engines also incorporate the 3900678 screw in their design. This screw is used to fasten various components, ensuring that the engine operates efficiently and reliably. The precise fastening provided by this screw is crucial for maintaining the structural integrity of these engines.

The 3900678 screw is a testament to Cummins’ commitment to quality and reliability, ensuring that their engines perform optimally under various conditions.

Role of Part 3900678 Hexagon Flange Head Cap Screw in Engine Systems

The part 3900678 Hexagon Flange Head Cap Screw is instrumental in securing various components within engine systems, ensuring their stability and proper function.

• Aftercooler: This screw is used to fasten the aftercooler to its mounting bracket, ensuring efficient cooling of compressed air before it enters the engine.
• Air cleaner strap: It plays a role in securing the strap to the engine block or frame, maintaining the integrity of the air filtration system.
• Air intake accessories: It is employed to attach components such as sensors or additional filtration elements, ensuring they remain in place and function correctly.
• Air intake manifold: The screw is utilized to secure the manifold to the engine, facilitating the smooth flow of air into the combustion chambers.
• Compressor air inlet arrangement: It ensures that the inlet is securely attached, allowing for optimal air compression and engine performance.
• Cove system: This screw is used to fasten the cove to the engine, protecting internal components from debris and ensuring efficient operation.
• Valve assemblies: It secures valve covers and other components, maintaining the valve’s operational integrity.
• Electronic governor system: The screw is used to attach the governor to the engine, ensuring precise control over engine speed.
• Engine balancer: It secures the balancer to the crankshaft, reducing vibrations and enhancing engine smoothness.
• Engine control wiring harness: The screw is utilized to secure the harness in place, protecting the wiring and ensuring reliable electrical connections.
• Exhaust manifold: It fastens the manifold to the engine, ensuring efficient exhaust gas flow.
• Fluid doser system: The screw is used to attach the doser to the engine, facilitating the precise injection of fluids for emission control.
• Flywheel housing: It secures the housing to the engine, ensuring the flywheel operates smoothly.
• Fuel control system: The screw is utilized to attach fuel control components, ensuring accurate fuel delivery.
• Fuel filter location: It secures the fuel filter in place, maintaining clean fuel supply to the engine.
• Fuel filter plumbing: The screw is used to attach plumbing components, ensuring secure and leak-free connections.
• Fuel pump drive: It secures the drive mechanism to the engine, ensuring reliable fuel pump operation.
• Fuel shutoff valve: The screw is utilized to attach the valve to the engine, ensuring secure and reliable fuel shutoff.
• Fuel system accessories: It secures various accessories to the engine, ensuring they function correctly.
• Fuel transfer right-hand engine kit: The screw is used to attach components, ensuring efficient fuel transfer.
• Long block kit: It secures various components within the kit to the engine, ensuring they are properly installed.
• Lubricating pump kit: The screw is utilized to attach the pump and related components, ensuring efficient lubrication.
• Overhaul kit: It secures components during the overhaul process, ensuring they are correctly installed.
• Refrigerant compressor: The screw is used to attach the compressor to the engine, ensuring efficient refrigerant compression.
• Throttle valve: It secures the valve to the engine, ensuring precise control over air intake.
• Torque converter oil cooler: The screw is utilized to attach the cooler to the engine, ensuring efficient cooling of the torque converter fluid.

Conclusion

The 3900678 Hexagon Flange Head Cap Screw by Cummins is a vital component in commercial truck applications, ensuring the stability and reliability of various engine and truck systems. Its design, material properties, and functionality make it suitable for withstanding the rigors of truck operation, contributing to the overall performance and safety of the vehicle. Regular maintenance and proper installation practices are essential to ensure the longevity and reliable performance of this Cummins part.