A bolt alone isn’t always enough to hold two or more parts together. While some bolts are self-anchoring, such as lag bolts, most require a nut. You can drive a bolt through the parts. You can then twist a nut onto the end of the bolt.
Nuts, however, aren’t foolproof. When exposed to vibrations, they may loosen or even fall off. Fortunately, clinch nuts are designed to resist vibrations while offering a more secure hold than traditional nuts.
What Are Clinch Nuts?
Also known as self-clinching nuts, clinch nuts are threaded fasteners that “clinch” the surface of the object with which they are used. Unlike traditional nuts, they typically aren’t hex-shaped. Instead, most clinch nuts are round. Clinch nuts are also able to withstand vibrations without loosening, making them a popular choice for aerospace-related applications.
Benefits of clinch nuts include the following:
- Resistant to vibrations
- High strength-to-weight ratio
- Can be used with materials that are too thin to be tapped for threads
- Easy to install
- Can be installed flush with objects
How Clinch Nuts Work
Clinch nuts are characterized by a ring of serrations. On the bottom of a clinch nut is an undercut and ring of serrations. These serrations act like teeth by biting into the object’s surface, thereby holding the clinch nut in place.
To use a clinch nut, you’ll need to create a shallow mounting hole in the object. You can then place the clinch nut — position the nut with the serrations facing down — inside of the mounting hole. Using a press tool, you can then apply a squeezing force to the nut. This will force the serrations to bite into the object.
Common Applications for Clinch Nuts
Clinch nuts are commonly used in applications where vibrations are a concern. Airplanes, for instance, often use them in their construction. Seats, access panels, avionics systems and other aircraft parts are often fastened with clinch nuts.
Clinch nuts are also commonly used in the heating, ventilation and cooling (HVAC) industry. Both residential and commercial HVAC systems often use them. Clinch nuts are commonly used to secure HVAC housing units, fans, ducts and other components.
In addition to airplanes, clinch nuts are commonly used in the construction of automobiles. Everything from bumpers and side panels to seat belts and engine mounts may feature them. Like airplanes, automobiles produce vibrations that can loosen traditional nuts. Clinch nuts are designed to resist vibrations such as this.
