Whenever you are working with fasteners, you want to be sure you have a strong, durable rivet or bolt that is suited to the job. Blind threaded inserts are among the most versatile types of fasteners, and there are thousands of types from which to choose. Choosing the right threaded insert depends on the nature of the materials you are working with and the application.
If you have devices that need to be disassembled and reassembled or that use particularly soft materials, threaded inserts offer a number of advantages, especially if the connection is load-bearing. Flexible plastics, for example, have difficulty holding a threaded bolt because the threads in the tap hole aren’t durable enough. Rather than relying on threads drilled into the soft workpiece itself, a threaded insert gives you more strength and more versatility, and tends to be more resilient over time.
Designed with Automation in Mind
Blind threaded inserts can be installed from one side, enabling faster installation, especially in a production line. They offer a stronger alternative to weld nuts and tapped holes, and they provide a stronger bond than self-tapping screws. In fact, threaded inserts are usually the strongest and least time-consuming fasteners used in any manufacturing setting, especially because they were designed for automation.
Threaded inserts have ribbed walls that offer greater strength under load. They can be used at virtually any stage of production, including after a workpiece is painted or coated, because they don’t require reworking once they are installed. That’s why blind threaded inserts have become so popular in applications such as aerospace, defense, transportation, clean energy, medical applications, and electronics.
Types of Threaded Inserts
There are a variety of different types of threaded inserts, each with a different design for a specific application.
- Rivet nut inserts, sometimes referred to as blind rivet nuts, can be installed from one side of a joint and have a counter-threaded interior designed to accept a bolt. Some rivet nuts will bulb on the blind side to create a solid connection. Others are designed to pull the rivet nut into the sleeve as they are tightened. Rivet nuts were first used to connect thick-walled materials in the 1930s, when RIVNUT® came into extensive use in aerospace manufacturing. Thin-walled inserts came later in round, hexagonal, and square designs and offer added versatility, such as using sealant under the head or special plating for greater durability in harsh conditions. They also come in a knurled body design for a better grip on the material.
- Eurostyle inserts are round-body threaded inserts with a semi-hexagonal, fully hexagonal, heavy hexagonal, or square body design. They are available from a variety of manufacturers, including Avdel, Atlas, and Sherex Fastening Solutions.
- Slotted body threaded inserts are designed with gashes in the body that expand when the bolt is tightened for a firm connection. There are straight-body and pre-bulbed body types from manufacturers such as Avdel, Atlas, Sherex, AVK, Goebel, and Marson.
- Molly Jack threaded nut inserts are designed for use with thin, brittle, or soft materials and are perfect for the assembly line. They are available in steel, brass, and coated steel, and when tightened, the sides collapse against the hole walls to form a permanent, reusable threaded insert. They can be installed by hand or using pneumatic tools without distorting thin materials.
- Stud-style threaded inserts also are available for any type of application with different thread sizes, head types, lengths, and materials. Bay Supply carries a variety of stud-style inserts from major manufacturers such as Atlas, AVK, Goebel, and Marson.
- Well-nut threaded inserts are useful for sealing holes or limiting vibrations. The well-nut insert is passed through one of the pieces of material and the nut is inserted from the flanged end. The non-flanged end is inserted into the second piece of material. As the bolt is tightened, the flange expands to prevent the insert from turning and the bushing is compressed to form a tight seal around the bolt hole.
- Riv-Float® threaded inserts are made by Sherex Fastening Solutions for off-center applications in which two pieces of material need to be connected but the holes fail to align.
Choosing the Right Threaded Insert
In addition to different configurations, threaded inserts also come in different materials for different uses.
Brass inserts, for example, are ideal for wood and particle board. Threaded plastic inserts are used for applications such as telecommunications and instrumentation because they are nonconductive and the threads create a lasting hold and can be assembled and disassembled with minimal wear. Stainless steel inserts, on the other hand, are used in molding and metal working, often for repair jobs or manufacturing. Stainless steel also is useful for clean applications such as food and beverage processing because it resists corrosion.
Blind threaded inserts are designed for production efficiency as well as durability, and can be incredibly versatile. If you need help choosing the right threaded insert for the task, an experienced distributor can help you weigh your options and select the right one.