CNC Machined Prototypes

When to Use Threaded Inserts in CNC Machined Prototypes

CNC Machined Pr
Image Source: Tik precision

Threaded inserts are an essential component in many CNC machined prototypes. They provide strength, durability, and versatility when it comes to joining different parts together. However, it is important to understand when and why threaded inserts should be used in CNC machined prototypes. We explore the benefits and considerations of using threaded inserts, as well as alternative solutions for different scenarios now.

Understanding Threaded Inserts

CNC Machined Prototype

Threaded inserts are cylindrical metal components with a threaded interior that allows for the attachment of bolts, screws, or other threaded fasteners to connect one component to another. They are particularly useful in devices that require frequent disassembly and reassembly or when working with softer materials that may not provide sufficient strength for direct threading.

There are different types of threaded inserts available, each with its own unique characteristics and applications. One commonly used type is the helical insert, also known as a Heli-Coil. Helical inserts feature diamond-shaped cross-sections and are made from high-grade stainless steel wire. They mechanically roll into a thread shape similar to a spring, providing excellent strength and durability.

Benefits of Threaded Inserts

There are several benefits to using threaded inserts in CNC machined prototypes:

Strength and Durability: Threaded inserts provide enhanced strength and durability to the connection point, especially when working with softer materials like aluminum or plastic. They create a larger contact surface, making them stronger than the original thread.

Ease of Installation: Threaded inserts can be easily installed using the appropriate tools and techniques. They can be embedded into the larger part, and their external surfaces are designed to grip the material and resist loosening forces.

Versatility: Threaded inserts can be used at any point during production, even after coating or painting. They can also be used in applications that require frequent disassembly and reassembly, making them ideal for prototypes that undergo testing and iteration.

Repair and Maintenance: Threaded inserts can repair internally threaded holes that have been damaged, avoiding the need to dispose of entire components. They also provide better tightening performance and prevent further thread damage.

Factors to Consider

While threaded inserts offer many advantages, there are certain factors to consider before deciding to use them in CNC machined prototypes:

Cost: Threaded inserts can add to the overall cost of the prototype due to the price of the inserts themselves and the additional installation charges. It is important to evaluate the budget and determine if the benefits outweigh the cost.

Lead Time: The installation of threaded inserts can take additional time, especially in large-scale production. It is crucial to consider the lead time and how it may impact project timelines.

Material Compatibility: Threaded inserts may not be suitable for all materials. While they work well with softer materials, they may not provide sufficient strength for certain applications or materials. It is important to assess the compatibility of threaded inserts with the specific material being used.

Alternative Solutions: In some cases, alternative solutions like standard drilling and tapping may be more cost-effective and functional for CNC machined prototypes. It is essential to evaluate different fastening methods and choose the one that best meets the requirements of the project.

When to Use Threaded Inserts

Threaded inserts are best suited for CNC machined prototypes in the following scenarios:

Frequent Disassembly and Reassembly: If the prototype will undergo frequent disassembly and reassembly, threaded inserts provide a reliable and durable solution. They allow for easy removal and reinsertion of bolts or other threaded connections without damaging the components.

Soft Materials: When working with softer materials like aluminum or plastic, threaded inserts offer enhanced strength and durability. They prevent stripping or damaging of the threads, extending the lifespan of the prototype.

Applications Requiring Strength and Stability: Threaded inserts are ideal for applications that require strong and stable connections. They provide additional strength to load-bearing areas and prevent fastening devices from loosening, making them suitable for aerospace, defense, and other high-stress applications.

Repairing Damaged Threads: If the prototype has internally threaded holes that have been damaged, threaded inserts can be used to repair and restore the functionality of the threads. This avoids the need to scrap or replace entire components, saving time and resources.

Still have questions about CNC machining threaded inserts for prototypes? We’ll be happy to assist you.

Alternatives to Threaded Inserts

While threaded inserts have their advantages, there are alternative solutions for different scenarios in CNC machined prototypes:

Standard Drilling and Tapping: For simpler applications that do not require frequent disassembly or work with soft materials, standard drilling and tapping can be a more cost-effective and efficient solution. It eliminates the need for additional installation of threaded inserts.

Press Fits and Dowel Pins: In some cases, press fits or dowel pins can be used to join multiple components in CNC machined prototypes. Press fits provide a secure and tight fit, while dowel pins are used for alignment and locating purposes.

Thread Locking Fluid: To ensure additional security and protection against loosening or corrosion, thread locking fluids like Loctite can be applied to fasteners. They provide an adhesive bond that keeps the fasteners in place, especially in applications that experience vibration or impact.


Threaded inserts are valuable components in CNC machined prototypes, providing strength, durability, and versatility in joining different parts together. They are particularly useful in applications that require frequent disassembly and reassembly or when working with softer materials. However, it is important to consider the cost, lead time, material compatibility, and alternative solutions before deciding to use threaded inserts. By carefully evaluating the requirements of the project, you can determine if threaded inserts are the right choice for your CNC machined prototype.

Learn about our 5 axis machining services.

Ready to talk about your next project?