A rivet nut is a unique type of rivet, sometimes known as a blind rivet nut, a threaded insert, a rivnut, or a nutsert. It is tubular, internally threaded, and counterbored so it can be driven just like a blind rivet from one side. However, there are various types of rivet nuts from multiple manufacturers, so it’s important to understand some of the nuances.
Like blind rivets, rivet nuts are driven through pre-drilled holes from one side of a workpiece. They are commonly used in aviation for applications such as inspection of access covers or to replace weld nuts. The advantage of using rivet nuts is that they do not require hot welding, so they can be installed in metal, plastic, fiberglass, and other materials without a problem.
A Rivet Nut by Any Other Name …
There are two basic types of rivet nut: one forms a bulge on the back side as a screw is tightened on its threads, and the other is drawn into a sleeve to create the connecting bulge on the back side.
Beyond those two basic types, there is a large selection of rivet nuts on the market, and they are known by many names, including blind rivet nut inserts, bling nuts, threaded inserts, riv float nuts, molly jack nut inserts, Eurostyle inserts, and more.
Rivet nuts offer a number of advantages that make them suitable for various applications where other blind rivets won’t do. We’ve already mentioned aviation manufacturing, but rivet nuts can also be used for appliances, automotive manufacturing, office furniture, playground equipment, solar installations, electronics, boats, pools and hot tubs, military equipment, and even bicycles.
Rivet nuts are more versatile than self-tapping screws or pressed inserts. They can be made from steel, stainless steel, brass, and other materials, and are not affected by heat, which makes them more convenient for applications such as plastic or wood where conventional welding is impractical.
In some manufacturing settings, rivet nuts are preferred because they enable faster assembly at reduced costs. Rivet nuts were made to be automated and can be used with a six-axle robot or other automated assembly tools.
Choose the Right Rivet Nut Tool
There are many powered rivet nut tools to use with rivet nuts.
With the “spin-spin” tool, the rivet nut is threaded onto a mandrel, fitted into the workpiece, and driven home using a pneumatic power tool. The mandrel spins, pulling the threaded position of the shank to form a bulge around the unthreaded portion. Once the rivet nut is in place, the mandrel spins in the opposite direction, to completely secure the rivet nut.
The “spin-pull” tool also threads the rivet nut on the mandrel and is inserted through a pre-drilled hole. Pressure is applied to pull to a specified distance so that the rivet nut forms a bulge, then the mandrel spins in the opposite direction to disengage the rivet nut. This approach works particularly well with plastic workpieces and other applications.
Finally, the “pull-to-pressure” tool is similar to the spin-pull tool. Instead of pulling to a pre-set distance, it pulls to a pre-set pressure. This tool is commonly used when working with metal or hard plastics.
When choosing your rivet nut tool, you need to consider whether you need a power tool or a hand tool. If you need a power tool, decide whether you need one that is battery operated. Most rivet nut tools come with multiple nose sizes and should fit the mandrel you need. When choosing the right tool, you should consider factors such as the work site, the types of materials you are working with, and—most important of all—ease of use and safety.
Consider how you plan to use the rivet nuts. If you are working in a shop or in one location, a powered tool might be just what you need. If you are working on a job site, portability is a factor, so a battery-operated tool might be a better choice. You will also need to consider power if you want a more efficient tool that lets you change rivet nuts quickly. Also consider how frequently you will be using the tool and whether it makes sense to invest in a heavy-duty tool if you plan to use it every day.
For some applications, a manual rivet nut tool might be all you need. For example, the Astro 1427 Hand Rivet Nut Kit is inexpensive and has changeable nose pieces to accommodate different sizes of rivet nuts. This tool has a 13-inch dual handle and applies pressure much as you would with a bolt cutter, generating enough force for many aluminum or stainless steel rivet nuts.
If you aren’t sure what you need, working with a trusted and reputable distributor can help you find the right rivet nut and the right rivet nut tool to meet your needs. Furthermore, a top-notch distributor offers great customer service—they’ll be with you before, during, and after your purchase.