Finding the right fastener for a project requires more thought and deliberation than you would expect. Finding the right fastener can seem impossible, especially when trying to fasten thin or brittle materials together. This is where rivet nuts shine. From use in aerospace and automotive manufacturing to furniture and consumer goods, rivet nuts are an innovative and easy fastening method that’s both revolutionized and simplified how products are assembled. In this article, we dive deeper into rivet nuts and discuss everything there is to know about them – from what they are and how they’re used to different types of rivet nuts and their advantages.
What are Rivet Nuts?
Rivet nuts, alternatively known as RIVNUTs®, were developed by the BF Goodrich Company in the late 1930s. Also called blind rivet nuts or threaded inserts, rivet nuts are internally threaded components that are completely anchored on one side. Originally used to secure deicing boots to aircraft wings, rivet nuts have since been adapted into many different forms and types for various fastening applications.
Rivet nuts are derived from standard rivets and are paired with standard sized bolts. Rivet nuts can have round, square, splined, or hexagonal bodies. Because it’s considered a blind fastener, rivet nuts are used in applications where only a single side of the workpiece is accessible. This makes rivet nuts one of the most versatile fastening devices that exist.
How do Rivet Nuts Work?
Like a normal rivet, rivet nuts are punched into a workpiece to fasten two or more materials together. The difference between a rivet and a rivet nut is that the rivet nut is only punched into a single piece of material, not all the constituent materials to be joined. Once the rivet nut is installed into one material, the remaining materials to be joined can be fastened with an externally threaded fastener, like a bolt, to the rivet nut. It’s that simple.
The simplicity in how rivet nuts are used to fasten materials together is what makes them so versatile. It can be argued that rivet nuts are easier to use and better at joining materials together than self tapping screws or pressed inserts.
How to Install Rivet Nuts?
To install a rivet nut, have a drill, appropriately sized drill bit, and a rivet nut tool available. Installing rivet nuts is as easy as following the 5 steps below:
- Drill a pilot hole with the same diameter as the rivet nut to be used in the workpiece.
- Take the rivet nut and thread it until flush onto the mandrel of the rivet nut tool.
- Pull the opposite end of the mandrel as far back as allowed and thread the adjuster back to contact it.
- Install the rivet nut using the rivet gun by inserting the rivet nut into the drilled pilot hole and squeezing the handles of the tool until it reaches a stop.
- Remove the rivet nut tool by unscrewing the mandrel from the rivet nut.
Be careful not to apply too much force on the rivet nut during installation as this may ruin the internal threads of the rivet nut.
When are Rivet Nuts Used?
Rivet nuts can be used to fasten a variety of materials together – including different types of metals, plastics, fiberglass, and carbon fiber. Like a normal rivet, rivet nuts are blind – as in, only one side of the workpiece is visible when installing the rivet nut. While the rivet nut will be permanently fixed to the material it is attached to, materials assembled to the rivet nut via a bolt, pin, or other devices can be removed.
Because of their light weight, small size, and easy installation, they are often used in applications where weight reduction is critical (i.e. aerospace and automotive). Additionally, rivet nuts can have high shear and tensile strengths, making them ideal for load bearing applications. This makes them also great for use in furniture, certain consumer goods, and electronics. While weight reduction and load-bearing are certainly advantages of using rivet nuts, manufacturers can also benefit from reduced costs due to faster assembly. Rivet nut installation can even be automated through 6-axis robots or other automotive processes.
Different types of Rivet Nuts
Round Rivet Nuts: These nuts are made for circular holes and have a smooth or knurled surface on the shank of the nut. Knurled surfaces provide greater spin-out resistance by gripping the installation material. Round rivet nuts can be made either with open or closed ends. Closed-ended rivet nuts provide a barrier for liquid or particles entering the blind side of the installation material.
Hexagonal Rivet Nuts: Hexagonal (hex) rivet nuts, like round ones, provide great spinout resistance and are used for hexagonal shaped holes. Hexagonal rivet nuts have hexagonal shaped shanks and are usually designed for more load bearing applications.
Slotted Rivet Nuts: Slotted rivet nuts come with slots cut into the shank of the rivet nut body. These often come pre-bulbed for a secure grip and easier installation. Slotted rivet nuts offer an extensive grip range ideal for fastening varying thickness materials.
Floating Rivet Nuts: Floating rivet nuts allow for flexible fastening of workpieces. In these types of nuts, there is room for the internal thread to be positioned at differing angles, allowing for flexible bolt installation.
Rivet Nut Studs: Composed of two pieces, rivet nut studs contain the rivet nut and an externally threaded stud. When the rivet nut is installed, the stud allows conventional fasteners, like standard hex nuts, to be mated onto the threaded stud.
While finding the right fastener for your project may be a challenge, it doesn’t have to be. Rivet nuts provide an innovative and flexible fastening method that rivals traditional methods such as the use of bolts or welds. Rivet nuts are easy and cost effective to install, have exceptional tensile and shear strengths, and enable the function of many of the goods and modes of transportation we use every day. Contact an Albany County Fasteners sales representative today to discuss which rivet nut is right for your project.