Insert Molding

Carefully inspect assembled plastic parts and you’ll often find threaded inserts.  These small metal pieces play a critical role in holding together the products we use every day, from your laptop to a variety of hand-held devices. 

Installing inserts into a plastic part can be tedious.  One method is to mold the plastic part and then manually secure the inserts into the part in the assembly stage.  A more cost-effective and efficient way to install inserts into a plastic part is through insert molding.  

How It Works 

Insert molding is the manufacturing process of installing inserts into the plastic part during the injection molding process.  The mold is specially designed to hold the inserts in place, allowing plastic to flow and harden around the inserts. A completed part is then ejected from the machine with the inserts installed.  This process eliminates the need for post-production assembly and ensures a tight bond between the plastic part and its inserts.

Plastic part with insert
Plastic part with insert


Insert molding can reduce cost and save you manufacturing time.  Because parts come out of the injection molding tool with the inserts already installed, post-processing labor is greatly reduced and parts can be packaged for shipment much quicker.  The process also provides more consistent part quality compared to manual assembly or the use of fixtures.

Vertical Molding 

Most plastic injection molding is done on horizontal presses, but vertical presses are highly recommended for insert molding.  Loading inserts into a horizontal press can be tedious and a tool must be specially designed to hold the inserts in place during the molding process.  With vertical molding, molds open and close on the y-axis, allowing gravity to do the work of holding inserts in the mold.

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Tenere Inc.

Tenere is a leading North American contract manufacturer of custom mechanical solutions for companies that connect our world through technology in the Cloud Infrastructure, Network Architecture, Fiber Optics, Self-Serve Kiosk, Autonomous Transportation, and Alternative Energy markets by leveraging our expertise in prototyping, design for manufacturability, tooling, production, assembly, and supply chain.

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Ⓒ Tenere Inc. 2019

Ⓒ Tenere Inc. 2019