3900620
Hexagon Head Cap Screw
Cummins®

Introduction

The Hexagon Head Cap Screw is a common fastening component used extensively in commercial trucks. It plays a role in maintaining the structural integrity and operational efficiency of vehicles by securely joining various components. This overview focuses on the 3900620 Hexagon Head Cap Screw by Cummins, highlighting its design, function, and significance in truck maintenance.

Basic Concepts of Hexagon Head Cap Screws

A Hexagon Head Cap Screw is characterized by its hexagonal head, which allows for efficient tightening and loosening using standard tools such as wrenches or sockets. The screw’s design includes a threaded shaft that engages with internal threads in the fastened material, providing a secure connection. Typically, these screws are made from materials like carbon steel, alloy steel, or stainless steel, each offering different properties such as tensile strength, corrosion resistance, and durability ¹.

Purpose of the 3900620 Hexagon Head Cap Screw in Truck Operation

The 3900620 Hexagon Head Cap Screw by Cummins is utilized in various applications within commercial trucks. It plays a role in assembling and maintaining critical components such as engine mounts, chassis parts, and body panels. Its robust design ensures that these components remain securely fastened under the demanding conditions encountered in truck operation ².

Key Features of the 3900620 Hexagon Head Cap Screw

The 3900620 Hexagon Head Cap Screw features a hexagonal head that provides a firm grip for tools, facilitating easy installation and removal. The screw’s threading specifications are designed to ensure a tight and durable connection. Cummins employs specific manufacturing processes to enhance the screw’s performance, including precision machining and quality control measures to ensure consistency and reliability ³.

Benefits of Using the 3900620 Hexagon Head Cap Screw

Utilizing the 3900620 Hexagon Head Cap Screw offers several advantages. Its durable construction contributes to long-term reliability, while its design resists loosening over time, even under vibration and stress. The screw is compatible with standard tools, simplifying the installation and maintenance processes ⁴.

Installation and Usage Guidelines

Proper installation of the 3900620 Hexagon Head Cap Screw involves several steps to ensure a secure fastening. Begin by aligning the screw with the designated hole, then use a wrench or socket to tighten it to the recommended torque specification. It is important to follow manufacturer guidelines to avoid over-tightening, which can damage the screw or the fastened material.

Troubleshooting and Maintenance

Common issues with Hexagon Head Cap Screws include loosening, corrosion, and damage from improper installation. Regular inspection and maintenance can help identify these problems early. To prolong the lifespan of the screw, ensure it is properly torqued and protected from environmental factors that may cause corrosion.

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 of innovation and commitment to quality, Cummins serves a wide range of industries, including commercial trucking. The company’s product range and dedication to excellence make it a trusted name in the automotive industry.

Cummins Engine Compatibility with Part 3900620

The Cummins part 3900620, a Hexagon Head Cap Screw, is designed to fit seamlessly with a variety of Cummins engines. This part is integral in ensuring the structural integrity and operational efficiency of these engines. Below is a detailed overview of the engines that are compatible with this specific part.

Compatible Engines

• 4B3.9
• 6B5.9
• 6C8.3
• B3.9 G
• B5.9 G
• B5.9 GAS PLUS CM556
• B6.7S
• C8.3 G
• G5.9
• G5.9 CM558
• ISB CM550
• ISB5.9G CM2180
• ISBE CM800
• QSB5.9 CM550
• QSV91-G4 CM558/CM700 V102
• QSV91G
• V903

Grouping of Compatible Engines

Group 1: 4B3.9, 6B5.9, 6C8.3, B3.9 G, B5.9 G, B5.9 GAS PLUS CM556, B6.7S, C8.3 G, G5.9, G5.9 CM558, ISB CM550, QSB5.9 CM550

These engines share a common design philosophy and architecture, making them compatible with the Hexagon Head Cap Screw part 3900620. This group includes a range of models that benefit from the robust and reliable fastening provided by this part.

Group 2: ISB5.9G CM2180, ISBE CM800, QSV91-G4 CM558/CM700 V102, QSV91G, V903

This group comprises more advanced and specialized engines that also require the precision and strength offered by the part 3900620. These engines, while differing in some specifications, still align with the design requirements that make this screw an essential component.

Application Considerations

When using the Hexagon Head Cap Screw part 3900620 in these engines, it is crucial to ensure proper installation and torque specifications are followed. This will maintain the engine’s structural integrity and operational efficiency. Regular maintenance checks should be performed to verify that the screw remains in good condition and has not loosened over time.

Role of Part 3900620 Hexagon Head Cap Screw in Engine Systems

The part 3900620 Hexagon Head Cap Screw is instrumental in securing and maintaining the integrity of various components within engine systems. Its applications span across multiple areas, ensuring that parts remain firmly in place under operational stress.

Alternator Location

In the alternator setup, the Hexagon Head Cap Screw is used to secure the alternator to its mounting bracket. This ensures that the alternator remains stable and aligned correctly with the engine’s pulley system, facilitating efficient power generation.

Bracket and Gearshift/Lifting Mechanisms

For brackets supporting gearshift or lifting mechanisms, the screw plays a vital role in maintaining structural rigidity. It helps in withstanding the dynamic loads and vibrations that occur during operation, ensuring the longevity and reliability of these components.

Camshaft and Cam Follower

Within the camshaft assembly, the Hexagon Head Cap Screw is employed to secure cam followers and other related components. This ensures precise alignment and reduces wear, contributing to smooth engine operation and consistent valve timing.

Air Cleaner and Compressor

In air cleaner and air compressor systems, the screw is used to attach covers and housings. This not only protects internal components from debris but also maintains airtight seals, which are essential for optimal performance.

Air Intake Connection

For air intake systems, the screw secures connections between various sections, ensuring there are no leaks. This is particularly important for maintaining the correct air-fuel ratio, which is critical for engine efficiency.

Cosmetic and Functional Covers

Cosmetic covers, such as those over the engine balancer or other performance parts, are often secured using this screw. Functionally, it prevents covers from dislodging, which could lead to damage or reduced performance.

Fuel and Oil Filters

In fuel and full flow oil filter assemblies, the Hexagon Head Cap Screw is used to secure filter housings. This ensures that filters remain sealed and operational, preventing contaminants from entering the engine.

Injector and Long Block Assemblies

For injectors within long block assemblies, the screw ensures that injectors are held firmly in place. This is essential for precise fuel delivery and combustion efficiency.

Radiator and Service Block

In radiator and service block applications, the screw is used to secure components that are subject to thermal expansion and contraction. This maintains the structural integrity of these parts, ensuring they function correctly under varying temperatures.

Short Block Variants

Across various short block configurations—whether 6C, 6Cart, 6CTA, or part of a short block kit—the Hexagon Head Cap Screw is utilized to secure critical components. This includes attaching covers, brackets, and other elements that are essential for the short block’s operation.

Ignition System

Within the ignition system, the screw is used to secure components such as coil mounts and spark plug wires. This ensures reliable ignition and consistent engine performance.

Overall, the part 3900620 Hexagon Head Cap Screw is a versatile fastener that contributes to the secure assembly and reliable operation of numerous engine components.

Conclusion

The 3900620 Hexagon Head Cap Screw by Cummins is a critical component in the maintenance and operation of commercial trucks and engines. Its robust design, compatibility with various Cummins engines, and versatile applications make it an essential part for ensuring structural integrity and operational efficiency. Proper installation, regular maintenance, and adherence to torque specifications are key to maximizing the benefits of this part.