Threaded inserts are small but mighty components that play a crucial role in fastening applications across various materials. Whether you're working with plastic, metal, wood, stone, or composite, threaded inserts provide a reliable and robust way to create a strong connection for screws and bolts. In this article, we'll delve into what threaded inserts are, their types, and their uses in different materials to help you choose the best solution for your application.


What Are Threaded Inserts?

Threaded inserts, also known as threaded fasteners or screw thread inserts, are cylindrical components that provide a threaded hole for a fastener. They are often installed into softer materials to enhance their load-bearing capabilities or to repair a stripped thread. By creating a durable and reusable thread, these inserts help in securely fastening components while reducing the risk of damage to the base material.


Benefits of Using Threaded Inserts

Using threaded inserts in your projects offers numerous advantages:

  • Increased Strength: They provide a stronger connection in softer materials by distributing the load more evenly.
  • Longevity: Threaded inserts allow for screws and bolts to be removed and reinserted into a drilled hole multiple times, extending the life of the existing hole.
  • Corrosion Resistance: Inserts made from non-corrosive materials, such as brass, stainless steel, or aluminium, extend the lifespan of connections in environments exposed to moisture or chemicals.
  • Repairability: They can be used to repair damaged or stripped threads, making it possible to reuse the same location.
  • High performance: Threaded inserts can reinforce the connection of screws and bolts in materials that are likely to come under strain.
  • Versatility: Suitable for various materials including plastic, metal, wood, stone, and composite, making them ideal for a wide range of applications.

Types of Threaded Inserts

Threaded inserts come in several types, each designed for specific applications, material characteristics and installation methods. The most common types include:

  • Heat Installed Inserts: Used mainly in thermoplastics, these inserts are installed by heating them until they melt into the plastic. Once cooled, they form a secure bond with the material.
  • Ultrasonic Installed Inserts: These are installed using ultrasonic energy that melts the plastic, allowing the insert to be embedded securely.
  • Cold Installed Inserts: These inserts are pressed into pre-drilled holes and rely on friction to stay in place. They are commonly used in harder materials like metals, hardwoods and thermoset plastics. Useful when a strong interference fit is required, typically in steel or aluminium.
  • Moulded In Inserts: Designed to be moulded in during the moulding process, these inserts have a blind end to prevent any plastic entering the internal thread.
  • Self-Tapping Inserts: These inserts are designed to cut their own threads as they are installed. They can be directly installed into a drilled hole without the need for pre-tapping and can be a great alternative if you don’t have access to any specialist installation equipment. They work well in plastic and wood materials.
  • Wire-Thread Inserts: Used to repair damaged threads in metal parts. They offer a strong internal thread while being lightweight and easy to install.

Now let's explore how these inserts are applied in specific materials.


Threaded Inserts for Plastic

Plastic materials are commonly used in various industries, including automotive, electronics, and consumer products. However, plastic’s relatively low strength can make it challenging to create durable threads directly. This is where threaded inserts come into play.

The use of threaded inserts enhances the strength and longevity of plastic assemblies, making them suitable for repeated use. They can be used in high performance applications, where torque and pull-out are critical, helping maximise the load-carrying capacity of the insert. This maintains the structural integrity of the plastic part and ensures a long-lasting, secure assembly.

Which are the right inserts for plastic?

The type of threaded insert you use will depend on the category of plastic in the application. The two main categories are thermoplastics and thermoset plastics. Thermoplastics soften when heated and can be remoulded multiple times. For these applications, you would install the inserts using heat/ultrasonic, moulded in or self-tapping methods. Thermosets, on the other hand, are plastics that permanently harden after curing and cannot be remoulded. They would require the use of cold installed, moulded in or self-tapping inserts.

SHOP INSERTS FOR PLASTIC


Threaded Inserts for Metal

Metal is a widely used material in industries such as aerospace, machinery and automotive. Metal components often require a more durable threading solution, especially when working with softer metals like aluminium. Threaded inserts can enhance the strength and wear resistance of these metals, making them ideal for repeated disassembly. It’s also a great way to provide a thread in sheet of metal which otherwise would be too thin to hold a screw alone.

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Threaded Inserts for Wood & MDF

Wood and MDF are versatile materials used in furniture, construction, and cabinetry; however, wood threads can easily strip or wear out over time. Using a threaded inserts in wood or MDF applications provides a robust and reusable connection that can withstand frequent use.

Features of an insert used for wood, such as knurls and ridges on the outer surface, allows the insert to bite into the wood to prevent rotation or pull-out. You’re then left with a strong, reusable thread for the fastener.

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Threaded Inserts for Stone

Using threaded inserts in stone materials like granite, marble or concrete can be challenging due to their hardness and brittleness. However, with the right inserts, you can create a durable and reliable connection.

Ideal for masonry, sculptures, and architectural projects, these inserts enable secure connections in hard, brittle stone that would otherwise be difficult to fasten.

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Threaded Inserts for Composite Materials

Composite materials, like fibreglass and carbon fibre, are widely used in industries such as automotive, aerospace, and marine. By reinforcing fastener points, threaded inserts help extend the lifespan and reliability of composite components, even under high-stress conditions.

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Summary:

Threaded inserts are essential components that offer enhanced durability, strength, and repairability across a wide range of materials. Understanding the specific requirements of your material and choosing the right type of insert is crucial to achieving optimal results in your project.

Whether you're designing and engineering an automotive component, assembling furniture, or creating 3D printed prototypes, threaded inserts can significantly improve the performance and longevity of your fixings. Investing in the right insert not only ensures a secure fastening solution but also extends the life of your product by making it more adaptable to wear, stress, and environmental factors.

With the right knowledge and selection, threaded inserts can be the key to unlocking a world of robust and reliable fastening solutions in any material you work with. Our friendly team are happy to assist you in selecting the correct insert for your project. Please contact us or use our handy online tool which can help you find the right insert in just a few short steps.