ISO 9001:2015 Certified      |      ISO 13485 Certified in QMS for Medical Devices      |      AS9100D Certified in QMS for Aerospace and General Engineering Applications.

What You Should Know About Cable Assembly Overmolding?

by | Mar 28, 2024

Overmolding isn’t just about adding tough external elements; it’s a transformative technique that strengthens inner wires, enhances environmental resistance, and streamlines aesthetics – all in one go. From the delicate components powering your smartphone to the rugged machinery on a factory floor, overmolded cable assemblies play a critical role in ensuring seamless operation and extended product lifespans.

Let’s delve into the world of overmolded cable assemblies and explore their benefits, applications, and key considerations for integrating them into your next project.

Key Takeaways

  • Overmolding enhances cable assemblies, making them fluid-resistant for harsh environments.
  • Cable assemblies with overmolding withstand shock, vibration, and flexing without damage.
  • Overmolding adds aesthetic value with corporate logos and trade names.
  • 3D printing ensures overmold models meet application needs before production.

Overmolded cable assemblies

Regular cable assemblies are typically enough and work great, but if you need to upgrade, that’s where overmolded cable assemblies come into place.

Overmolding takes a regular cable assembly and encases it in a tough, protective shell, typically made of plastic or rubber.

Here’s how this super suit is made:

Mold Prep: The cable assembly, with its wire harnesses and connectors, is placed inside a specially designed mold.

Plastic Power Up: Molten plastic, as the heating element, is injected into the mold.

Cooling Down: Once the plastic cools and hardens, it forms a secure, one-piece unit around the cable assembly.

Benefits Of Using Overmolded Cable Assemblies

We mentioned how cable overmolding creates a protective shield for your assembly manufacturing process, but what superpowers does it grant? Here’s how overmolding benefits your cable management.

  • Super Strength: The overmold acts like a shield, protecting the delicate wires to withstand shock, environments, bumps, and even moisture. No more worries about nicks, cuts, or environmental hazards.
  • Bending Benefits: Overmolded cable assemblies strengthen the connection points, preventing damage from pull strength or continual flexing, especially near the cable exit points.
  • Sealed Tight: No more dust, moisture, or other particles sneaking in to mess with the electronics inside. The outer casing acts as a secure seal, keeping the termination point and everything protected.
  • Lifespan Upgrade: Safeguarding the wires and connections extends the lifespan of your overmolded cables.
  • Strain Relief: It provides extra support to the overmolded connectors, reducing strain from pulling or bending.
  • Aesthetics Advantage: Overmolded cable assemblies can create a clean and professional look for your cable assemblies. Plus, it can incorporate color-coding or logos for easy identification.
  • Smaller Size: In some cases, overmolding can create more compact wire harnesses compared to traditional methods. This is ideal for tight spaces where bulk can be an issue.

While there might be an initial cost increase, the extended life, additional protection, and overall reliability of overmolded cable assemblies often prove to be cost-effective.

Power Up Your Project: Find Expert Cable Assembly Contract Manufacturers in Chennai.

Benefits of cable assembly overmolding

Cable Overmolding Process

Overmolded cable assemblies elevate standard cables into robust units by encasing them in a protective shell. This process, known as injection molding, creates what we call overmolded cables. Overmolding offers superior durability, strain relief, and environmental resistance, making it ideal for demanding applications like medical equipment(s) and consumer electronics. Here’s a detailed breakdown of the overmolding process for custom cable assemblies:

Mold Design and Tooling

  • Design Engineers: The process starts with design engineers meticulously crafting specialized mold tooling. This tooling is typically made of hardened steel to ensure longevity and withstand the high pressures involved.
  • Mold Cavity Design: The mold features precisely designed mold cavities. These cavities mirror the exact shape and dimensions of the desired final overmolded cable assembly, including the cable layout and termination points. The mold may even incorporate designated areas for pre-molded components like screws or clips for later attachment.

Cable Assembly Preparation

  • Component Selection: The cable assembly itself is meticulously prepared. It involves selecting the appropriate wires, choosing the right connectors, and potentially incorporating dedicated strain relief features to safeguard critical connection points.
  • Precise Positioning: The prepared cable assembly is then carefully positioned within the designated mold cavity. It ensures all components are aligned correctly for optimal over-molding and to achieve a seamless final product.

Injection Molding Machine

  • The Workhorse: The core of the process is the injection molding machine. This machine acts as the workhorse, responsible for transforming raw material into the final cable overmolding.
  • Molding Material Selection: A hopper within the machine is filled with the chosen molten PVC. This material is often a thermoplastic like thermoplastic polyurethane (TPU), known for its flexibility and durability.
  • Heating and Melting: The molding resin is fed into a heated chamber called the heated barrel. Inside the barrel, an injection screw rotates and applies friction, generating heating elements that melt the material into a viscous liquid called molten resin.

Injection and Molding Cycle

  • Injection Process: Once the molten resin reaches the desired temperature and consistency, the injection ram applies high pressure. These force the plastic resin out of the heat shrink and inject it into the mold cavities surrounding the positioned cable assembly.
  • Pressurization and Cooling: The mold resin remains clamped shut under high pressure throughout a predetermined molding cycle. This pressure ensures the molten resin fills all cavities and bonds securely with the cable overmolding components. During this cycle, the resin cools and becomes hardened steel molds.

Tired of Making Stuff? Let the Top Contract Manufacturers handle it for you.

Part Ejection and Finishing

  • Ejecting the Overmolded Assembly: After the molding cycle is complete, the mold automatically opens, and the newly formed overmolded cable assembly is ejected.
  • Finishing Touches: Any final touches or post-processing steps are then performed. These involve trimming excess material from the overmolded plastic or incorporating features like corporate logos or color-coding for easy identification.


Overmolded cables offer a powerful solution to create robust and reliable cable assemblies for demanding applications. By understanding the intricacies of the process, from mold design to material selection, you can ensure your custom cable assemblies achieve optimal performance.

If you’re looking for a trusted partner to navigate the overmolding process, Violin Technologies can help. Our team of experts possesses the experience and resources to design, manufacture, and deliver high-quality overmolded cable assemblies that meet your specific needs.

Contact us today to discuss your project requirements.

Frequently Asked Questions (FAQs)

What is the process of cable overmolding?

Overmolding strengthens cable assemblies by encasing them in a protective shell. The cable and overmolded connectors are placed in a mold; then hot liquid plastic is injected to form stable connections and one piece unit.

What is the difference between inserting and overmolding?

Insert molding uses pre-made inserts placed in a mold before plastic injection. Overmolding, in contrast, directly molds plastic around a whole cable assembly in one go.

What is the difference between molding and overmolding?

Regular molding creates a complete product in one go. Overmolding, however, is a multi-step process. It involves molding a base part first (pre mold) and then injecting another material to form a protective layer around it.

Almaas Saleem |author

Almaas Saleem

About the Author

Almaas Saleem is a skilled software engineer from Kerala, India who currently resides in East Africa. She is passionate about technology and constantly seeks to learn more about it through reading and hands-on experience. Almaas excels in web development, design, automated testing software, ethical hacking, cybersecurity, and digital marketing. She also works as a technical writer for new businesses, managing various entities. Almaas is distinguished by her steadfastness and commitment to her work, which consistently ion.