How To Install Threaded Inserts In Plastic

April 19th, 2022By E-Z Lok

There are numerous applications that call for threaded inserts for plastic. Whether you are working with 3D printing, thermoset plastics or post-fabrication molds, there are several uses for thread inserts to be used in your projects. In this guide, we discuss how to install threaded inserts in plastic. Learn more about the different kinds of plastic inserts to find the right one for your needs.

What Are Threaded Inserts For Plastic?

Used by numerous industries, threaded inserts are a common type of hardware used to create strong machine threads in plastic components. Plastic inserts are used in materials that would otherwise be too thin to have threads machined into them, or they are used to repair worn-out fastenings in corroded materials.

How Plastic Inserts Work In 3D Printing

When creating the model for your 3D printing application, the design should include pilot holes in all the locations you wish to have a plastic insert. Hole size recommendations can be found on our website. These sizes are a general guideline. We recommend testing to determine the exact size needed prior to production. You will typically use brass threaded inserts for 3D printing projects and set them after the part has been fabricated.

Unlike thermoset plastic, thermoplastics like the ones used in 3D printing can be melted and reformed multiple times without negatively affecting the durability of the plastic. In contrast, thermoset plastics go through chemical reactions during the heating and cooling process and cannot be melted again, so they require inserts to be placed before they cool or to use non-thermal installation processes like press inserts.

What Are Threaded Inserts for Plastic Made Of?

When learning how to install threaded inserts in plastic, you have to consider what your inserts are made of. The most common metals used for self-tapping threaded inserts for plastic are brass or stainless steel. While other materials could be used, these offer the best combination of corrosion resistance, durability and grip strength in plastic applications.

Brass Threaded Inserts for Plastic

Brass threaded inserts for plastic can be used in all manner of applications, including as press-in inserts for thermoset plastic. They can also be inserted using heat for thermoplastics (or as press-in inserts for either material).

Stainless Steel Threaded Inserts for Plastic

While they offer higher corrosion resistance, stainless steel threaded inserts for plastic are less common than their brass counterparts. They are less prone to warping under mechanical stress and can be used outdoors without concern.

Installing Threaded Inserts for Plastic

Plastic threaded inserts come in two categories: Ultrasonic (or Heat-Set) inserts and Press Inserts. Using the right plastic insert for your application is important to ensure grip strength and security. Here are some of the most common installation methods.

Ultrasonic and Heat-Set Inserts

Designed for use in thermoplastics, these thread inserts are placed using an ultrasonic horn. The horn vibrates at a high frequency, generating heat via friction with the threaded insert. The heat melts the plastic surrounding the insert as it is placed. The insert then cools rapidly, creating a firm seal.

Great for thermoplastic use such as 3D printing, heat-set inserts are set in place by heating and setting the plastic insert into the thermoplastic. As it cools, the plastic hardens and creates a strong bond with the insert.

Press Inserts

Capable of being used in thermoset plastics and thermoplastics, these threaded inserts for plastic have a very simple installation process. Apply pressure to the top of the plastic insert until it is placed in the desired location. These are commonly used in thin plastic products such as signs, advertisements and displays.

Get Threaded Inserts for Plastic From E-Z LOK Today

Now that you know how to install threaded inserts in plastic, trust E-Z LOK for the products you need to get the job done. We are a global leader in hardware fastenings for plastic, metal and wood. Our threaded inserts for plastic provide superior holding power for post-molding installations, reducing costs and cutting out waste from rejected parts. Get plastic inserts for all varieties of thermoset and thermoplastic materials. Whether you are working with 3D printing or in creating marketing displays, we have the threaded insert for plastic that's the best choice for you.

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