Types of Threaded Inserts: Choosing the Right Solution
Threaded inserts are designed to create strong, reusable internal threads in materials that might otherwise strip, wear out, or fail under load. At E-Z LOK™, threaded inserts are engineered to work with specific materials and performance requirements, including soft wood, aluminum, cast iron, and plastics.
Understanding the different types of threaded inserts — and how they function — makes it easier to choose the right solution for your application.
Threaded Inserts for Metal
When working with softer metals such as aluminum, magnesium, or cast iron, reinforcement is often necessary. Over time, especially with repeated assembly and disassembly, original threads in these materials can be stripped or wear down.
Solid Wall Inserts
Solid wall inserts are heavy-duty components with both internal and external threads. Their one-piece construction and Loctite thread-locker provides excellent resistance to pull-out and torque.
They are commonly used for:
- Repairing stripped threads
- High-load applications
- Industrial tools and machinery
Helical Coil Inserts
Helical inserts are wire-formed coils that create precise internal threads once installed. They are ideal when maintaining thread accuracy and minimizing added diameter is important.
They are frequently used in:
- Aerospace applications
- Automotive components
- Precision assemblies
Key-Locking Inserts
These inserts feature locking keys that are driven into the base material after installation. This mechanical locking feature prevents rotation and provides strong resistance in high-vibration environments.
Threaded Inserts for Wood
Wood inserts are designed with features that securely anchor into hardwood, plywood, and composite materials, ensuring a strong and reliable hold.
Common features include:
- Coarse or knife-style outer threads
- Compatibility with soft and hard woods as well as composites
- Easy installation using a hex drive, screwdriver, or dedicated E-Z LOK drive tools
They are often used in:
- Furniture manufacturing
- Cabinetry
- Fixtures that require repeated assembly
- Point of Purchase/Retail Displays
Installing a threaded insert in wood allows the use of machine screws, creating stronger and longer-lasting connections compared to wood screws alone.
Threaded Inserts for Plastic
Plastic materials benefit from inserts that prevent cracking while distributing load evenly.
Heat-Set/Ultrasonic Inserts
These inserts are installed using heat; supplied by either a heating element or ultrasonic vibration. During installation, the surrounding plastic softens, allowing the insert to be pressed in and then solidifies around the retention features of the insert as it cools, creating a strong bond.
Press-In Inserts
These inserts feature knurled or barbed outer surfaces that grip the material securely when pressed into place.
Mold-In Inserts
These inserts are placed on core pins within an injection molding machine prior to the plastic being injected. They offer the highest performance of any type of insert for plastic.
Inserts for Plastic are widely used in:
- Electronic enclosures
- Consumer products
- Injection-molded components
Threaded inserts allow plastic components to withstand repeated fastening without stripping.
Inserts Designed for Different Installation Methods
Threaded inserts also vary based on how they are installed.
Screw-In Inserts
Installed into tapped holes using standard tools. Many E-Z LOK inserts include self-locking features for added security.
Self-Tapping Inserts
These cut their own threads during installation, reducing preparation steps.
Press-Fit Inserts
Installed by pressing into a pre-formed hole.
Locking Inserts
Designed to provide increased resistance in high-load or high-vibration environments.
Material and Performance Options
E-Z LOK offers threaded inserts in several material options to meet different application requirements:
- Carbon steel for high strength
- Stainless steel for corrosion resistance
- Thin-wall designs for limited space
- Heavy-duty options for demanding repairs
Selecting the right insert depends on load requirements, base material, thread size, environmental conditions, and preferred installation method.
There are many types of threaded inserts, each engineered to solve specific fastening challenges. Whether reinforcing metal threads, adding machine threads to wood, or strengthening plastic components, the right insert improves durability and long-term performance.
E-Z LOK provides threaded insert solutions that are strong, efficient, and easy to install — making secure, reusable threaded connections possible across a wide range of applications.