18 Jan 2023

What are threaded inserts?Example of threaded inserts on bolts.

Threaded inserts are small, often cylindrical, parts that you can insert into a hole in a plastic part during the molding process to provide a threaded hole for a screw or bolt. Threaded insert design typically uses metal, such as steel, brass, or aluminum inserts, and comes in various thread types and sizes. You can install them into a plastic part using multiple methods, including ultrasonic welding, heat staking, and press-fitting.

What are threaded inserts used for?

People use threaded inserts to provide a strong and durable thread in plastic parts, which can be assembled and disassembled multiple times without losing strength. People commonly use them in the automotive, aerospace, and electronics industries and in consumer goods, such as toys and appliances. Parts with these types of inserts often use them for additional assembly or when you need to incorporate a metal piece into the plastic part to complete the unit. 

Designing threaded inserts for plastic molding 

two threaded inserts can be seen in this handicap door activator.

When designing these types of inserts for plastic molding, it is important to consider the type of plastic you can use, the size and shape of the insert, and the method of installation. The insert should also have a design to withstand the stresses of the molding process and the end-use application. A good design will consider how to install the insert into the plastic part. It’s also important to use the right type of metal for the insert, as it will affect the thread’s strength and the insert’s overall durability.

How to install threaded inserts in plastic

In plastic injection molding, you add inserts on during the molding process. After you design the mold to accommodate for the inserts, you must calibrate the machine. Then each plastic part will have its insert installed as it exits the mold. Proper installation of the these types of inserts will ensure that it can withstand the stresses of the end-use application and provide a strong and durable thread for assembling and disassembling the plastic parts multiple times. If needed, the operator can install threaded inserts after they mold the part.

How strong are threaded inserts

Threaded inserts design should be strong and durable. It should also be able to withstand the stresses of the molding process and the end-use application. They can provide a reliable thread for multiple times assembling and disassembling plastic parts. The strength of the insert will depend on the material and design used. Steel is typically the strongest metal that people use, but the material will vary based on application.

four threaded inserts are used for this GPS cover.

Threaded Inserts for Plastic Molding with Rex Plastics

Threaded inserts for plastic molding are an important component for many industries. Providing a strong and durable thread for assembling plastic parts. When designing these types of inserts, it is important to consider a few things. The type of plastic, size and shape of the insert, and the method of installation are all important. With the correct design, they can provide a reliable and long-lasting thread for your application. If you have a plastic part with these types of inserts in mind, reach out today for a quote!