Field assembly cable or custom overmolded cable assemblies? It’s a question that we receive at Circuit Assembly often. While we’re always happy to consult with customers to help determine the best type of assembly for their application, we thought a blog on the topic could also help shed some light on the debate. In this post, we’ll discuss the basics of cable overmolding and field assembly. We’ll also discuss key factors for deciding between each.
Field Assembly Cable: What You Need to Know

Whether you’re already familiar with field assembly cables or you’re still learning about it, it’s never a bad idea to review its basics. Specifically, it consists of a housing that is screwed in or clipped on. It’s also normally assembled by hand. As you might expect, field cable assembly can be faster because there’s less of a need for setup. However, this type of assembly generally isn’t ideal for high-volume applications due to its labor-intensive nature.
Ideal Application
Field assembly is ideal for low-volume production applications. This is especially true if you’re looking at a faster development time and hope to prototype quickly. If your upfront investment is minimal and you’re able to quickly prototype, you can always revisit the design if modifications are necessary.
Pros and Cons
As we said, the field assembly sweet spot is low-volume production. The use of an expensive molding machine isn’t necessary. However, being that the process is more labor-intensive, overall labor costs may be higher.
Overmolded Cables: What You Need to Know

As you may already know, the overmolding process works by melting down a large sum of plastic. Then, a mold is created and high-pressure plastic is inserted into the mold to create the right cable. It’s an ideal process for high-volume work. End parts are often more durable and have greater seal strength as well.
Ideal Application
As we noted above, an overmolded cable assembly is ideal for high-volume work. It’s not a cost-effective production method for low-volume work or limited order runs.
Pros and Cons
The biggest advantage of custom overmolded cable assemblies is that it’s very economical and efficient for producing high-volume orders. Though there’s more setup involved, the upfront costs of pre-production more than make a high-volume order worth it in the end. Disadvantages to the process include the upfront pre-production work that must be carried out before the part run.
Choosing the Right Assembly
There are various production questions you should be asking yourself when it comes to choosing the right cable assembly. Depending on how you answer them will likely help dictate what type of assembly is best for you. Here’s a look:
- What is the production quantity? As we indicated above, field assembly is ideal for low-volume production. Conversely, cable overmolding is better for high-volume production.
- Do you need process flexibility? If there’s the potential of revisiting the design and prototypes, field assembly lends itself much better to this flexibility.
- Known requirements: Factors such as durability, materials, and use cases should all factor into assembly choice. For instance, medical and solar applications are better suited for overmolded cables. Audio/video and high power/voltage end uses are better suited for field assembly. Seal strength should also be considered. Stronger seals can better endure water and dust and are synonymous with molded assembly.
- Prototyping speed: If you want to use field assembly, it’s better to create a prototype faster than working with an overmolded cable assembly.
Factors to Consider
There are five main factors that need to be considered when deciding between overmolded and field assembly cable:
- Cost: Balance the costs of labor-intensive work versus that of tooling and setup.
- Run length: As we discussed, field assembly is better for low-volume production. Overmolded is better for high-volume production.
- Durability: Generally, molded cable assembly tends to be stronger. The field cable assembly can be improved to enhance durability; however, there are limitations.
- Materials: Field cable assembly is usually comprised of metal or plastic parts. Molded assembly is generally crafted from more durable parts and has higher IP ratings.
- Flexibility: When you’re working with molded cable assemblies, you have what you get. In other words, no repairs can be made. Field cable assemblies can be repaired or modified if there are any issues.
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Contact Us Today
For more information on the difference between field assembly and overmolded cable assembly, contact us at Circuit Assembly today.
We’re ready to work with you, understand your application and recommend the best production method.