3941981
Hexagon Flange Head Cap Screw
Cummins®

The Hexagon Flange Head Cap Screw (Part #3941981), produced by Cummins, is a specialized fastener designed for use in commercial trucks. This article provides an overview of this Cummins part, its purpose, key features, benefits, and maintenance suggestions.

Basic Concepts

A Hexagon Flange Head Cap Screw is a type of bolt characterized by a hexagonal head and a flanged base. The hexagonal head allows for efficient tightening using a wrench or socket, while the flange provides additional surface area for load distribution and prevents the screw from sinking into the material ¹.

Purpose and Function

The 3941981 is utilized in various applications within commercial trucks. It plays a role in securing components and assemblies, ensuring structural integrity and reliable performance. Common uses include fastening engine components, transmission parts, and chassis elements ².

Key Features

• Hexagonal head for easy wrench or socket engagement.
• Flanged base for enhanced load distribution and prevention of sinking.
• High-strength material construction for durability in demanding applications.
• Precise threading for secure and reliable fastening.

Benefits

• Improved load distribution due to the flanged design.
• Enhanced tightening efficiency with the hexagonal head.
• Increased durability and resistance to wear and corrosion.
• Reliable performance in high-stress environments typical of commercial trucks.

Troubleshooting and Maintenance

Regular inspection of Hexagon Flange Head Cap Screws is recommended to ensure continued performance and safety. Look for signs of corrosion, loosening, or damage. Tighten screws to the manufacturer’s specified torque settings using the appropriate tools. Replace screws showing significant wear or damage to maintain structural integrity ³.

Compatibility

The 3941981 is designed to fit various Cummins engines, providing a secure fastening solution for different engine applications. It is compatible with a range of smaller to mid-sized engines, including the 4B3.9, 6B5.9, B3.9 G, B4.5, B5.6 CM2670 B152B, B5.9 G, B5.9 GAS PLUS CM556, B6.7 CM2670 B153B, G5.9, and G5.9 CM558. Additionally, it fits a variety of ISB engines, such as the ISB (Chrysler), ISB CM2150, ISB CM550, ISB CM850, ISB/ISD4.5 CM2150 B119, ISB/ISD6.7 CM2150 SN, ISB5.9 CM2880 B110, ISB5.9 CM2880 B140, ISB5.9 CM2880 B149, ISB5.9G CM2180, ISB6.7 CM2250, ISB6.7 CM2350 B101, ISB6.7 G CM2180 B118, ISBE CM2150, and ISBE CM800.

Role of the 3941981 in Engine Systems

The 3941981 is integral in securing various components within engine systems, ensuring stability and reliable operation.

Connection Points

This screw is often used at connection points where secure fastening is required. For instance, it plays a role in attaching the air crossover to the engine block, ensuring a tight seal that prevents air leaks and maintains efficient airflow.

Exhaust System

In the exhaust system, the Hexagon Flange Head Cap Screw is employed to fasten the exhaust outlet to the manifold. This secure attachment is vital for maintaining the integrity of the exhaust flow and reducing the risk of harmful emissions escaping.

Wiring and Harnesses

When it comes to the electronic control module (ECM) wiring and harnesses, this screw ensures that connections remain firm and undisturbed. This is particularly important in high-vibration environments typical of engine compartments.

Long Block and Short Block Kits

In both long block and short block kits, the Hexagon Flange Head Cap Screw is used to secure various components. Whether it’s attaching auxiliary systems or ensuring the water pump is firmly in place, this screw contributes to the overall structural integrity of the engine assembly.

Turbocharger and Plumbing

For turbocharged engines, the screw is utilized in turbocharger plumbing to ensure that all connections are secure. This is essential for maintaining the pressure integrity of the turbo system and preventing leaks that could compromise performance.

Water and Recirculation Systems

In water pump and recirculation systems, the Hexagon Flange Head Cap Screw helps in securing components that are subject to constant fluid flow and pressure. This ensures that the system operates efficiently without the risk of component detachment or failure.

Conclusion

By understanding the applications of the 3941981, engineers and mechanics can better appreciate its importance in maintaining the structural and operational integrity of various engine systems.