How to Prevent Hex Bolts from Loosening?

Hex bolts are one of the most commonly used fasteners in machinery, construction, and furniture assembly. Many people may wonder — how can a hex bolt be effectively prevented from loosening?
As a professional fastener manufacturer, Xinchi Fasteners is pleased to share several reliable anti-loosening methods for hex bolts, ensuring safe and long-lasting connections.

Hex Bolt

Friction Locking Method for Hex Bolts

The friction locking method is one of the most widely used anti-loosening techniques for hex bolts.
This method creates a constant positive pressure between the internal and external threads, generating friction that resists relative rotation.

Such pressure can be achieved through axial compression or simultaneous bi-directional compression of the threaded pair.
It’s simple, economical, and commonly applied to general-purpose hex bolts used in machinery and furniture joints.

Permanent Locking Method for Hex Bolts

This permanent locking method for hex bolts involves techniques like spot welding, riveting, or adhesive bonding.
While these approaches ensure the bolt never loosens during service, they come with a limitation — once assembled, the connection cannot be disassembled without damaging the fastener.

Therefore, this method is typically used in non-removable structures or applications where maintenance is not required.

Riveting and Punching Locking Method for Hex Bolts

In the rivet punching anti-loosening method, the hex bolt is tightened first and then secured by punching, welding, or gluing the bolt head or threads.
This process eliminates the relative movement of the threaded parts, forming a non-removable fixed joint.

However, its main drawback is that the bolt can only be used once, and disassembly is extremely difficult—it often requires breaking the fastener completely.
This method is suitable for critical components that must remain stable under vibration or load impact.

Mechanical Locking Method for Hex Bolts

The mechanical locking method is one of the most reliable techniques for important hex bolt connections.
It uses additional mechanical devices—such as cotter pins, lock washers, or safety wires—to physically prevent the bolt from rotating.

This approach ensures a high level of security and is often applied in aviation, automotive, and heavy machinery, where vibration resistance and reliability are crucial.

Structural Locking Method for Hex Bolts

The structural anti-loosening method does not rely on external devices but instead depends on the self-locking structure of the hex bolt itself.
A typical example is the Tang thread locking structure, where special thread geometry increases resistance to rotation and prevents loosening naturally.

This is considered one of the most advanced and effective anti-loosening methods for hex bolts today, combining high precision with easy installation and reusability.

Xinchi Fasteners Factory Advantages

As a professional hex bolt manufacturer and supplier in China, Xinchi Fasteners Co., Ltd. provides a complete range of bolts, nuts, and custom fastener solutions for industrial and furniture applications.

• Over 100 cold heading machines and a daily production capacity exceeding 10 million pieces
• Factory area of 30,000 m², with two modern six-floor production buildings
• Strict quality control systems following ISO and DIN standards
• Comprehensive solutions including non-standard fastener customization and surface treatment options (zinc plating, black oxide, etc.)

Whether for mechanical assemblies, furniture hardware, or construction use, Xinchi offers durable and reliable hex bolt products with excellent anti-loosening performance and competitive pricing.

Xinchi Fastener Factory

XINCHI is a trustworthy fastener company, especially in furniture nuts. We have a factory,  founded in 2007. We are the designated fastener supplier to“STAPLE”. As a trusted fastener supplier, XINCHI offers a wide range of high-quality fasteners, including nuts, screws, bolts, rivets, and washers. If you would like to learn more about fasteners or are interested in wholesale fasteners, please do not hesitate to contact us. Our experienced and expert service team will reply as soon as possible.