Plastic Insert Molding and Overmolding
Complex parts demand the right partner. Our process is built to help you reduce assembly complexity, improve part quality, and lower total program costs.
IATF 16949:2016 Certified | ISO 9001:2015 Certified
What is Plastic Insert Molding?
Insert molding is a plastic injection molding process in which a preformed component — typically a metal insert such as a threaded fastener, pin, or electrical contact — is placed into a mold before plastic is injected around it, encasing the insert and forming a single integrated part. The result eliminates the need for secondary assembly operations, reduces part count, improves bond strength, and produces more consistent finished components.
Primary Purpose: Create one assembly with a stronger bond and faster supply chain.
Common Applications: threaded metal hardware in plastic housings | embedded electrical components | hand tools with handles | automotive seat belts
What is Plastic Overmolding?
Overmolding is a plastic injection molding process in which one material is molded on top of a previously molded or formed substrate, typically plastic over plastic, or plastic over metal, to create a single multi-material part. Unlike insert molding, which typically encases a metal component, overmolding is most often used to add a second polymer layer for functional or aesthetic purposes. Overmolding can be performed in the same mold in sequence or as transfer molding, where the substrate is moved to a second mold for the overmold shot.
Primary Purpose: Create soft-grip handles, vibration dampening, water-resistant seals, multi-color surfaces, or enhanced ergonomics
Common Applications: screwdriver and toothbrush handles | medical device grips | automotive interior touchpoints
Bring us complexity. We’ll deliver simplicity.
Combining polymers in a single part and molding onto metal parts aren’t always straightforward. Our teams are always willing to think outside the box to bring your designs into reality with insert molding.
Material Selection
We always consider the melting points of different polymers to ensure that they are suitable for overmolding. If specified materials present problems during production, we can help guide you to choose alternatives that will have the necessary physical and mechanical properties for your application.
Streamline Your Supply Chain
We combine plastics, metals, and tooling expertise under one roof to make your job easier. You no longer have to worry about coordinating between separate stampers and molders or arranging your own tooling maintenance. When you work with LMC, we take care of it all.
Process Efficiency
Automated insert molding, when compared to secondary assembly, uses fewer parts, reduces the opportunity for error, and provides streamlined logistics for part tracking and shipping.
More than a plastic insert molding partner.
Industries Served
Insert molding and overmolding bring many modern assemblies to life in some of the world’s most demanding and critical industries.
Certifications and Approvals
We also supply components for every major automotive company worldwide.
Re-engineer your insert molding and overmolding results today.
Turn your problematic parts program into a profitable one…or make your next new product line a success. Tell us about your project to get started with a quote today!