PEM Rivet Nuts Manufacturers

What is the fastening principle of rivet nuts?

The fastening principle of rivet nuts is mainly based on the plastic deformation of materials. Riveting is a cold working process that joins two or more parts together through mechanical force without the need for melting or welding. The following is a detailed explanation of the tightening principle of rivet nuts:

Material deformation: Rivet nuts are often installed on thin plates or sheet metal parts. During installation, the mounting parts of the rivet nut (such as rivets or special installation tools) exert pressure on the material.

Plastic zone formation: When the applied pressure exceeds the yield strength of the material, the material begins to plastically deform. This means that the material undergoes a permanent shape change under pressure.

Fastening connection: With the plastic deformation of the material, the installation part of the rivet nut (such as the rivet head) will fit with the surface of the material, forming a tight mechanical interlock. This interlocking prevents the rivet nut from loosening or falling off.

Rivet Strength: The tightening strength of a rivet nut depends on a variety of factors, including the type and thickness of the rivet material, the size and design of the rivet nut, and the pressure exerted during installation.

Threaded Fastening: Rivet nuts themselves are often internally threaded and can be used with bolts or screws for additional tightening. The tightening effect of threads can further enhance the stability of riveted connections.

Riveting type: The installation of riveted nuts can be achieved through different types of riveting, such as closed riveting (blind riveting), open riveting, plug-hole riveting, etc. Each riveting method has its specific application scenarios and advantages.

Automated installation: In modern manufacturing, the installation process of riveted nuts is often completed through automated equipment to improve production efficiency and installation quality.

Quality control: The fastening quality of riveted nuts needs to be guaranteed through strict quality control, including monitoring of installation force, material deformation, thread tightening and other parameters.

The fastening principle of the rivet nut makes it a fast, reliable and economical fastening solution, especially for joining thin sheet materials that cannot be connected using traditional welding or bolting.

What mechanical and geometric parameters need to be considered when designing rivet nuts?

When designing rivet nuts, key mechanical and geometric parameters are considered that are crucial to ensure their functionality and reliability. Here’s a detailed explanation of a few key points:

Material selection: The material of the rivet nut has a significant impact on its performance. Commonly used materials include carbon steel, stainless steel, and aluminum alloys. Each material has its own specific strength, toughness, corrosion resistance and processing properties. For example, stainless steel rivet nuts are suitable for use in corrosive environments, while high-strength steel can be used where larger loads are required. Material selection also affects cost and weight, so these need to be weighed against the specific requirements of the application.

Dimensional specifications: Dimensions are the basic parameters in the design of rivet nuts, including diameter, length and thread size. Dimensions need to match the thickness of the material being joined to ensure adequate clamping force and avoid material damage. In addition, the size also affects the load-bearing capacity and installation space of the rivet nut. For example, a larger diameter rivet nut can provide higher load carrying capacity but may require more installation space.

Thread design: The thread is a key part of the riveted nut, and its design directly affects the fastening performance. The type of thread (such as ordinary thread, self-tapping thread), pitch and thread depth all need to be accurately calculated. The tightness and self-locking properties of the thread are critical to preventing the nut from loosening. In addition, the manufacturing accuracy of the threads will also affect the ease and reliability of installation.

Head design: Head design is not only related to the appearance of the riveted nut, but also to the convenience of installation and fastening efficiency. Head shapes such as round head, flat head, hexagonal head, etc. Each shape has its specific purpose. For example, a hex head design may offer more torque and better tool compatibility, while a round or flat head may be better suited for a smooth appearance or applications where space is limited.

Mounting hole diameter: The mounting hole diameter of the rivet nut is key to ensuring successful installation. A hole that is too large may cause the rivet nut to not hold securely, while a hole that is too small may cause installation difficulties or damage the material. The mounting hole diameter is usually slightly larger than the diameter of the rivet nut to allow appropriate plastic deformation of the material during installation.

Pre-tightening force: The pre-tightening force is the initial tightening force that can be achieved after the riveted nut is installed. Sufficient pre-tightening force can prevent the connection from loosening during work and is crucial to ensure the reliability of the connection. The amount of preload depends on factors such as operating load, vibration conditions and temperature changes.

Environmental factors: If the rivet nut will be used in a special environment, such as high humidity, high salinity or chemical corrosion environment, the impact of these environmental factors on the corrosion resistance of the material must be considered during design. In addition, temperature changes may also affect the mechanical properties of materials, so materials need to be selected to adapt to these conditions.

Safety factor: When designing rivet nuts, a certain safety factor also needs to be considered to ensure that the rivet nut can maintain its functionality even under the most adverse working conditions. The determination of the safety factor needs to consider factors such as material strength, working load, installation error and environmental impact.

Through comprehensive consideration and accurate calculation of these key parameters, a rivet nut can be designed that not only meets the needs of a specific application, but also has good performance and reliability.