Overmolding Ultimate Guide

Overmolding Ultimate Guide

Plastic and rubber accessories are our every day’s demand. In this case, we need electric wires, bottles, plastic cases, beautiful toys, cables, etc. to meet our daily demands. Therefore, depending on the structure of the accessories, we can manufacture them in different molding processes. We know the Molding machine has different types based on the complexity of the accessories. Among those, overmolding injection molding is comparatively popular than the other methods. In this article, we will be demonstrating the Overmolding Ultimate Guide for you.

Here, we will explain the detail of overmolding and its difference between other similar molding methods. At the end of this tutorial, you will find the best overmolding service provider in the USA. Additionally, we will highlight their locations so that you can quickly get them.

What is overmolding?

In an easy word, The injection process where the machine performs consecutive steps using two or more materials to create one object is the overmolding injection process. In this case, overmolding is mainly of two types, insert Molding and two or multiple shot overmolding. Consequtively, we will demonstrate the difference between the insert molding and the overmolding right after this section. To Understand this Overmolding, we should know the following three essential things for overmolding below.

Overmolding substrate

From the definition, we knew that overmolding is one type of injection process where the machine makes one single part from two or more materials. But how to distinguish the different shapes for different materials? That’s where we will need the substrate. In this case, we can use anything such as metal part, temporary molded plastic part. We can even use the existing product, such as threaded screws or electrical connectors.

This overmolding substrate is the first piece from where the single continuous part begins. later, it is composed of chemically bonded. Therefore, we can easily manufacture the required shape from mechanically interlocked materials of different types.

Overmolding materials

Before choosing the overmolding materials, we must think about its compatibility. In this case, if your materials don’t suit to the other material, you may end up with the deformation or other overmolding faults. Additionally, there are thousands of overmolding materials on earth, but the selection process involves skilled engineered resin specialists.

However, the most common overmolding materials are given below. Additionally, we have stated the compatibility chart so that you can easily distinguish your materials for your expected product. 

Chloride (PVC)
Durable, resistive to flame, chemical, tension
And abrasion.
Poor regulatory reputation
Stiff in cold weather
Cheap and versatile. High impact and wear
Resistance. Flexible for elongation.
Resistant to acids and bases.
Not ideal for UV exposure
brittle in cold temperature
Acrylonitrile Butadiene
Styrene (ABS)
Harsh, impact, and chemical resistance. Low shrink
And high stability.
Poor weather resistant
 Polyurethane (TPU)
High abrasion, oil, grease, and solvents resistant.
High elasticity
Not cost-effective
Rubber (TPR)
performs like rubber and process like plastics.
Slip and weather resistant. High shock absorption
And flexibility.
Prone to wrapping
Polybutylene Terephthalate
High strength, rigid and flexible. High resistant to
Fuels, oils, fats, and solvents.
Not ideal for thin parts
Collected from iconnsystems.com

Injection Overmolding Process

The general structure of the machine consists of three main parts – The input section, Melting Section, and the Injection section. Consecutively, the overmold materials get into the machine in pellet form. After that, it melts inside the cavity. At last, the rotating motor pushes the molten materials into the molds.

The common difference is in the input and mold section. Subsequently, the general injection molding machine injects one material. On the other hand, the overmolding device has the feature of multiple materials injection. Additionally, to create a different molding structure, we can use the overmolding substrate.

Cable Overmolding process

Cables are widely used materials because we need this every day. Therefore cable overmolding is also very popular in manufacturing industries. However, The process is straightforward. But the most critical factor to consider before doing the overmolding is selecting the materials compatible with the cable jacket and the molding materials.

The insert and injection process is similar to that of the other injection processes. In this process, the metallic portion covered with the jacked goes through the injection chamber and comes out with the molds. Moreover, it is durable and excellent resistance to the external environment.

Injection Overmolding vs. insert molding

Insert Molding is a part of overmolding. Here, you can say all the insert molding is overmolding, but all the overmolding is not insert Molding. To understand the differences, we think tabulation will be better than a paragraph explanation. 

 OvermoldingInsert Molding
Injection TypeThis process injects multiple materials to create one single part.This process inserts metal to place inside the mold.
Benefits1. Stable finishing
2. Durability is long.
3. Provides safety
4. Cost-efficient than post-molding fabrication
1. Assembly time is faster than
2. This process reduced the part size and weight
3. It is also cost-effective
ExampleRFID, phones, toys, PCB,
Power tools and Hand tools,
car steering wheels
Filters, vacuum hose connectors,
automobile ducts, heavy parts,
Medical Equipment

Benefits and application of the overmolding process

We have already mentioned a few benefits in the difference table. Now, let’s know all the necessary services for the overmolding process.

  1. The texture that we make for handheld items safer and user to use.
  2. We can design varieties of styles and colours for separate parts and finished products.
  3. We can customize the opportunities for customization.
  4. Undoubtedly it is vibration and noise-free.
  5. Overmolding protects from sharp corners and edges.
  6. It defends the internal mechanism from external damage.
  7. It is electrically resistive.
  8. Overmolding increases shock absorbency.
  9. It stands up to strain (approx. 360 degrees)
  10.  It increases the flexibility at the cable exit.
  11. Overmolding simplifies the installation by creating a one-piece assembly.
  12. There’s no chance of human error.

There are thousands of overmolding product uses we will encounter every day. It is not possible to mention all of them here. Therefore, we have categorized them into four main applications, where we will see overmolding in common.

  1. Medical instruments and devices. 
  2. Automated External Defibrillator (AEDs) Unit.
  3. Electrical Appliances.
  4. Communication and Navigation Devices.

Is Overmolding Right for your project?

It is a critical question that may come in your head. But think about your project first. And then consider the structural materials and components. in this point, if we consider the above four applications, overmolding is a cost-effective method to manufacture. Therefore, the overmolding is the best business method. It will make more than double your investment.

Top 10  injection molding companies with overmolding service

There is a good number of institutions that are providing various Molding services. Among those companies, we picked the most ten popular Inc. Here in this article, we will demonstrate a short description of each of the service providers. But before that, Let’s have a look at the summary table. Therefore, you may not need to go in detail to find their primary information.

Company BrandLocationsOther features
Mold and Engineering
24541 Maplehurst
Clinton Twp, MI 48036
Injection molding
Prototype Injection
CNC machining
3D Printing
Xometry7940 Cessna Ave
Gaithersburg, MD 20879
CNC machining
Sheet metal cutting
3D Printing
Injection Molding
Manufacturing Accelerated
Proto Labs, Inc., 5540
Pioneer Creek
Dr. Maple Plain,
MN 55359 USA
Injection Molding
CNC machining
Sheet metal fabrication
3D Printing
6415 Angola Road, HollandUrethane Casting
Compression Molding
CNC machining
Injection Molding
MED Device
Erie (5340 Fryling Road,
Suite 300 Erie, PA 16510)
Pittsburgh (2009 Mackenzie
way, Suite 280 Cranberry
Township, PA 16066)
Philadelphia (101 Gibralter
Road, Suite 100
Horsham, PA 19044)
Contract Manufacturing
3D additives
Package Sterilization
GSH Industries, Inc.15242 Foltz Industrial Parkway
Cleveland, OH 44149
Injection Molding
Rubber Extrusion
MSI Mold13170 West Star Dr
Shelby Township, MI 48315
Plastic and Protype Injection
Custom Injection
Design and engineer
Assembly and extra
Silicone Parts
9658 Premier Pkwy,
FL 33025
Shot and Multishot Injection
Rubber Injection
8150 West Ridge Rd.
Fairview, PA 16415
2012 East 33rd St.
Erie, PA 16510
Plastic Molding
Rubber Molding
Aluminium Die Casting
Casting sources
CNC machining
Rubber Industries, Inc.200 Cavanaugh Drive
 Shakopee, MN 55379 
Rubber Molding
Liquid Silicon Rubber
Silicon Injection Molding

Xcentric  Mold and Engineering

This company has varieties of overmolding services. Usually, they provide plastic over the plastic substrate, rubber over rigid substrate overmolding, Multi-color Overmolding, Cable overmolding, Overmolding plastic on metal, chemical, and mechanical bond overmolding, Medical instrument overmolding, etc.  This company has two different locations in the USA. In this case, depending on your position, you can choose the store nearby. After all, the website for Xcentric is fast and easy to access the support.


This company has multiple international stores. Additionally, they have a bunch of overmolding services. In this case, they work with some selective materials, such as Acetal Copolymer, Alloy Steel 4140, Aluminium 6061-T6, Carbon Steel, Simple shapes, Steels. Consecutively, the specific services they provide for overmolding are Overmolding plastic in metals, Medical Instrument Over moulding. Besides, they also offer other injection moulding services. 

Protolabs Manufacturing Accelerated

Protolabs specializes in injection molding, CNC cutting, and 3D printing. In this case, there is a bunch of injection molding services they used to provide. Among them, overmolding is one of the most common services. THerefore, they specialize in the Overmold design guide and over mould. Moreover, their website has complete knowledge of each of the services they provide. After all, they cleared everything about the way os services.


Another excellent service provider for overmolding is ICOMold Inc. In this case, they have well explained their services and categories on their website. Besides, they specialize in tooling and production, Overmolding, Insert Molding, Ultrasonic welding, Pad printing, Silk screening, Functional Testing by customer Specification. Moreover, the material they use for the overmolding application is hard plastic such as ABS, PC, etc. After all, ICOmold promises fast and dependable, trouble-free injection mold modification, low prices on plastic injection and plastic parts.

MED Device Online

MED Device specializes in Medical device Contract Manufacturing, Assemblies, kitting and packaging services, Injection molding, etc. In this casae, their overmolding services are not that vast like the top four institutions. But yet they focus on the overmold product for medical devices. Additionally, there is another section for designs and developments. Finally, if you are looking for overmolding products for medical purposes, then we will say overmold for medical devices will best here.

GSH Industries, Inc.

This manufacturing industry focuses on custom plastic, aluminium, and rubber extruded profiles and tubing. In this manufacturing technology, they have expertise in CNC machining and plastic injection in over 100 years of experience. However, it is located in Ohio, USA. Regarding this, they use all kinds of plastic materials. For example, CPVC, rigid, and flexible PVC, High Medium or low-density polyethene, Polystelene, Santoprene, Nylon, Polyurethane, PETG, Butyrate, Hyterel, Specialty engineered resins, TPE, TPR, TPO, ABS, Polypropelene, polycarbonate, Acrylic, Noryl.

MSI Mold

This manufacturing company focuses on Custom Plastic Injection Molding. Besides, it also provides other services like Plastic injection moulds, Prototype injection molding, Overmolding process animation. Additionally, they promise to deliver high-quality products from experienced and friendly employees. However, MSI molding is providing these services since 2005. Moreover, they have already shipped 6 million parts and assemblies to a long list of industries.

Simtec Silicone Parts

Simtec silicone parts company tells us that they specialize in silicone overmolding. In this case, it is a leading company of produced parts using the injection molding process. Consecutively, they have 15 years of experience and earned the capabilities to produce outstanding quality products. Additionally, they have well explained their services and production process on their website.

PHB Inc.

This company allows for cost-effective low-pressure overmolding services. In this case, they specialize in rubber overmold. Besides they have other services like CNC machining, custom assembly and others. The PHB market includes Railway, Appliances, Automotive, Electronic, Military, Aerospace, Medical, Safety Application, transportation and industrial products. Moreover, they make varieties of rubber products, such as Viton, Nitrile, Neoprene, Hycar, Silicones, NR, EPDM and Custom blends.

Rubber Industries, Inc.

Our last pick for overmold services is this Rubber Industries Inc. Here, this company focuses on rubber and silicone overmold. In detail, they specialize silicone to metal overmold, rubber to metal overmolding services, over-moulded rubber and silicone, etc. Moreover, they also provide injection molding, transfer molding, compression molding, liquid injection molding and so on. In this case, their most popular products are Silicone, LSR, Nitrile (NBR), HNBR, SBR, FKM (Viton), EPDM, Chloroprene Rubber (neoprene), natural rubber, etc.


The above table for the top 10 injection molding companies in the USA contains the location and the services provide by the respective institution. Therefore, if you are looking for the location only, we suggest you have a glance at the table. After all, this article will help you enough to get them easily. By the way, we hope we explained enough to get you the best service provider in the USA. This article surely will help you make your research easier. Depending on the specialized services, please find your demand first, and then look for the best service provider for your product.  

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