Insert Molding

Custom Insert Molding Services

JIAHUI proudly offers a range of insert mold services as a seamless extension of our injection molding capabilities. If you want to seek a thorough insert molding design review and a complimentary quote, we invite you to share your CAD files with us conveniently. Our accomplished team of injection molders stands ready to respond within a 24-hour window promptly.

With dedicated expertise, we specialize in meticulously integrating metal or plastic elements into molded components, underscoring enhanced structural integrity and a streamlined production process. Our custom insert molding solutions reflect precision and excellence.

  • Precision Fusion
  • Tailored Solutions
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Insert Molding -

What’s Insert Molding Process?

Insert molding is a plastic molding process involving molding or forming plastic parts around non-plastic components, often called inserts. These inserts can be simple objects like threads or rods and more complex components such as batteries or motors. The process enables combining different materials, such as metal and plastic, into a single integrated unit, offering advantages in strength, conductivity, wear resistance, and design flexibility.

The insert molding begins with inserting the non-plastic components into the mold cavity before the plastic injection molding occurs. The plastic material encapsulates the insert, creating a unified product. The process requires precise alignment to ensure accurate placement of the inserts, as even a slight misalignment can cause failure. Benefits of insert injection molding include improved component reliability, enhanced strength and structure, reduced assembly and labor costs, decreased part size and weight, and increased design flexibility.

Our Qualification For Insert Molding Service

Our qualifications for insert molding are a testament to our expertise and proficiency in this intricate manufacturing process. At JIAHUI, we have meticulously honed our capabilities to excel in every facet of insert molding. We ensure the seamless integration of diverse materials and components into a singular, high-quality unit.

Our skilled team of engineers and technicians brings a wealth of experience. We leverage cutting-edge equipment that enables us to maintain the strictest tolerances and attain impeccable alignment, which is crucial for the success of this process. 

Through meticulous planning, precise execution, and rigorous quality control, we consistently produce insert-molded products that surpass industry standards. Whether it’s aerospace, medical devices, electronics, or other specialized sectors, our insert molding solutions find their application in an array of fields. Seamlessly incorporating metal inserts and other components enhances plastic parts’ reliability, strength, and structural integrity, contributing to overall product durability and performance.

Manufacturing Process

Insert molding creates products by combining parts within a mold. Skilled technicians place inserts, often metal or plastic, in the mold. Molten plastic is injected, encasing the inserts. After cooling and solidifying, the mold opens, revealing the final piece with integrated components. This process enhances durability and functionality in various industries.

Material Weight Size Limit Surface Finish Wall Thickness
PA 0.012-1KG 500mmx500mmx300mm Ra1.6µm~0.1µm 0.02m~0.06mm
PE 0.012-1KG 500mmx500mmx300mm Ra6.3µm~0.1µm 0.02m~0.06mm
PS 0.012-1KG 500mmx500mmx300mm Ra3.2µm~0.05µm 0.02m~0.06mm
POM 0.012-1KG 500mmx500mmx300mm Ra3.2µm~0.05µm 0.02m~0.06mm
PBT 0.012-1KG 500mmx500mmx300mm Ra3.2µm~0.2µm 0.02m~0.06mm
PC 0.012-1KG 500mmx500mmx300mm Ra1.6µm~0.05µm 0.02m~0.06mm
PPO 0.012-1KG 500mmx500mmx300mm 0.02m~0.06mm 0.02m~0.06mm
PPS 0.012-1KG 500mmx500mmx300mm Ra3.2µm~0.2µm 0.02m~0.06mm
EP 0.012-1KG 500mmx500mmx300mm Ra3.2µm~0.2µm 0.02m~0.06mm
PF 0.012-1KG 500mmx500mmx300mm Ra3.2µm~0.2µm 0.02m~0.06mm
DAP 0.012-1KG 500mmx500mmx300mm Ra3.2µm~0.4µm 0.02m~0.06mm

Our Insert Molding Production Capabilities

We expertly combine various materials to create robust components that meet high-quality standards. Minimizing post-production steps enhances structural integrity, cuts costs, and accelerates time-to-market.

Materials for Insert Molding Parts

The materials chosen for insert molding parts span various categories. Engineering plastics like ABS, PC, and Nylon are favored for durability and wear resistance. This diverse material selection ensures optimal performance and durability across the electronics and automotive industries.

  • ABS
  • PVC
  • PE
  • PP
  • POM
  • PA
  • PC
  • PEEK


ABS is a thermoplastic material known for its strength, impact resistance, and toughness. It is widely used in various industries for its excellent mechanical properties, ease of processing, and versatility. ABS is commonly found in applications such as automotive parts, toys, electronics, and household appliances.


  • High-impact resistance and toughness
  • Good dimensional stability
  • Excellent chemical resistance
  • Easy to process and mold
  • Versatile and used in various applications, including automotive, electronics, and consumer goods.


PVC is a versatile thermoplastic material known for its durability, chemical resistance, and cost-effectiveness. It is commonly used in construction, plumbing, electrical insulation, and various consumer products. PVC can be flexible or rigid, making it suitable for multiple applications.


  • Excellent chemical resistance
  • High durability and long lifespan, even in harsh conditions.
  • Good electrical insulating properties
  • Versatile and can be rigid or flexible
  • Cost-effective and widely available


PE is a widely used thermoplastic material known for its excellent chemical resistance, low moisture absorption, and high impact strength. It is lightweight, flexible, and has good electrical insulating properties. PE is commonly used in packaging, pipes, automotive components, and various consumer products.


  • Excellent chemical resistance
  • High-impact strength and toughness
  • Low moisture absorption
  • Good electrical insulating properties
  • Lightweight and flexible


PP is a thermoplastic material known for its high chemical resistance, low density, and good thermal stability. It is lightweight, rigid, and has excellent moisture resistance. PP is commonly used in automotive parts, packaging, laboratory equipment, and various consumer products due to its versatility and cost-effectiveness.


  • High chemical resistance
  • Low density
  • Excellent moisture resistance
  • Good thermal stability
  • Versatile and cost-effective


POM, also known as acetal or Delrin, is a high-performance engineering thermoplastic known for its excellent strength, stiffness, and dimensional stability. It has low friction, good wear resistance, and is resistant to moisture, chemicals, and solvents. POM is commonly used in mechanical and precision parts, automotive components, and electrical applications.


  • High strength and stiffness
  • Low friction and wear resistance
  • Excellent dimensional stability
  • Good chemical resistance
  • Low water absorption


PA, commonly known as nylon, is a versatile thermoplastic material with excellent mechanical properties. It offers high strength, toughness, abrasion resistance, good chemical resistance, and dimensional stability. PA is widely used in various industries for applications such as electrical components, consumer goods, and automotive parts.


  • High tensile strength and toughness
  • Good chemical resistance
  • Low friction and wear resistance
  • Excellent dimensional stability
  • Good thermal stability


PC is a durable and transparent thermoplastic material known for its high impact resistance and optical clarity. It has good electrical insulating properties, excellent dimensional stability, and can bear a wide range of temperature. PC is commonly used in safety glasses, automotive components, and electronic enclosures.


  • High impact resistance
  • Optical clarity
  • Good dimensional stability
  • Electrical insulation
  • Wide temperature range


PEEK is a high-performance thermoplastic material known for its exceptional mechanical properties, chemical resistance, and high-temperature resistance. It offers excellent strength, stiffness, and dimensional stability, making it suitable for demanding aerospace, automotive, and medical applications.


  • High-temperature resistance
  • Excellent chemical resistance
  • High mechanical strength
  • Low flammability
  • Biocompatibility

Surface Treatment For Insert Molding Parts

Beyond the molding process, our insert molding solutions encompass a comprehensive range of post-processing options to enhance the functionality and appearance of the parts. Our offerings extend beyond mere cooling and ejection. We refine the final product through surface treatment techniques like painting, coating, or texture enhancement.


In-Mold Decoration(IMD)

In-mold decoration (IMD) is a surface finish method where decorative patterns or designs are applied to a plastic part during molding. This technique eliminates the need for secondary painting or printing operations, resulting in a durable, high-quality, and visually appealing finish.


Black, Grey, Red, Blue, Gold, White, Silver, Purple

Smooth, Matte finish

Out-Mold Decoration(OMD)

Out-mold decoration (OMD) is a surface finish method where decorative elements, such as graphics or patterns, are applied to the outer surface of a molded part. This technique involves placing a pre-printed film or foil onto the part's surface and then using heat and pressure to bond the decoration, creating a visually appealing and durable finish.


Black, Grey, Red, Blue, Gold, White, Silver, Purple

Smooth, Matte finish


Electroplating in surface treatment is when a metal coating is applied to a conductive surface through an electrochemical reaction. It involves immersing the object to be plated in a solution containing metal ions and using an electric current to deposit a metal layer onto the surface.


White, Black, Grey, Red, Yellow, Blue, Green, Gold, Silver, Bronze

Smooth, Semi-matte, Matte finish

Laser Carving

Laser carving is a surface finish method that utilizes laser technology to etch or engrave intricate designs onto a material's surface. It offers precise and detailed patterns, making it suitable for aesthetic enhancements or functional purposes, and is commonly used in various industries such as manufacturing, jewelry, and art.


Black, Grey, White, Yellow, Red, Blue, Green, Gold, Silver, Purple

Smooth, Matte finish


Printing_Insert Molding -

Printing is a surface finish method that involves transferring ink or other pigments onto a material's surface to create images, text, or patterns. It is a versatile technique used in various industries, such as packaging, advertising, textiles, and art, to add visual appeal and convey information.


Black, Grey, White, Yellow, Red, Blue, Green, Gold, Silver, Purple

Smooth, Matte finish

Non-conductive vacuum plating(NCVM)

Non-conductive vacuum plating (NCVM) is a surface finish technique that applies a thin metallic coating on non-conductive materials. It involves a vacuum deposition process to vaporize and deposit metal ions onto the substrate, enhancing conductivity and providing an attractive finish.


Black, Grey, White, Yellow, Red, Blue, Green, Gold, Silver, Purple

Smooth, Matte, Semi-transparent finish


Painting_Insert Molding -

Painting is especially suitable for the surface of the primary material of metal. It will strengthen the material's moistureproof& rust prevention functions and enhance its compression resistance and internal structural stability.


Black, Grey, White, Yellow, Red, Blue, Green, Gold, Silver, Purple

Smooth, Matte finish

Bead Blasting

Bead Blasting_Insert Molding -

Bead blasting in surface treatment is a process where fine abrasive particles, such as glass beads or ceramic media, are propelled at high speed onto a surface using compressed air. This abrasive action helps to remove rust, paint, or other contaminants, leaving behind a clean and textured surface finish.



Smooth, Matte finish


Texturing_Insert Molding -


Black, Grey, White, Yellow, Red, Blue, Green, Gold, Silver, Purple

Smooth, Buffed, Matte finish


Polishing_Insert Molding -

Polishing is the process of creating a shiny and smooth surface, either through physical rubbing of the part or by chemical interference. This process produces a surface with significant specular reflection but can reduce diffuse reflection in some materials.



Smooth, Semi-smooth, Matte, Textured finish

Excellent Insert Molding Services

Why settle for less? Choose JIAHUI for unmatched insert molding services. Your success is our priority.

Typical Insert Molding Products

Die Casting FAQs -

FAQs Related To Insert Molding

A: Designing and selecting an automated insert molding system requires thoughtful consideration of some factors to ensure efficient, successful operation. Here are some precautions to remember:

1.Component Design:

  • Design for Manufacturability: Ensure that the design of the insert and the surrounding plastic components is suitable for the insert molding process. Consider factors such as proper insert placement, sufficient draft angles, adequate wall thickness, and appropriate material selection to ensure successful molding and proper component functionality.

2.Insert Selection:

  • Material Compatibility: Choose inserts that are compatible with the molding material to prevent issues such as material degradation, poor adhesion, or dimensional instability.
  • Insert Design: Consider the geometry, size, and weight of the inserts to ensure they can be handled appropriately, positioned, and retained during the molding process. Avoid designs with sharp edges or undercuts that could hinder the insertion or ejection process.

3.Molding Machine Selection:

  • Capacity and Capability: Select a molding machine that can accommodate the required insert size, weight, and production volume. Consider factors such as clamping force, injection capacity, and shot size to ensure proper molding of the inserts and the surrounding plastic material.
  • Automation Features: Look for molding machines with automation features such as robotic insert handling, pick-and-place mechanisms, and precise positioning capabilities to ensure accurate and efficient insert placement.

4.Mold Design:

  • Insert Positioning and Retention: Design the mold to securely hold the inserts in place during the molding process. Consider features such as insert pockets, grooves, or mechanical locking mechanisms to ensure proper insert positioning and prevent movement or displacement during molding.
  • Venting and Cooling: Pay attention to venting and cooling design to ensure proper gas evacuation and effective heat dissipation, which can impact the quality and dimensional stability of the molded parts.

5.Process Validation and Optimization:

  • Trial Runs: Conduct thorough process validation and optimization trials to determine the optimal process parameters, including injection pressure, temperature, and cycle time. This will help ensure consistent quality, minimize defects, and maximize production efficiency.
  • Quality Control: Implement robust quality control measures to monitor and inspect molded parts, including dimensional accuracy, insert positioning, and bond integrity. This will help identify any issues early on and ensure the final product meets the required specifications.

Considering these precautions during the design and selection process, you can improve the chances of success and achieve efficient and reliable production in an automatic insert molding system. Working closely with experienced mold designers, molders, and automation experts is also advisable to ensure the best results.

A: There are a variety of materials that can be used for insert molding, depending on the specific requirements of the application. Here are some commonly used materials for insert molding:


  • Polypropylene (PP): PP is a versatile thermoplastic that offers good chemical resistance, low density, and excellent impact strength. It is commonly used in automotive, consumer goods, and electrical applications.
  • Polycarbonate (PC): PC is a transparent, impact-resistant thermoplastic with good dimensional stability. It is often used in applications that require clarity, such as automotive lighting, electronic housings, and medical devices.
  • Acrylonitrile Butadiene Styrene (ABS): ABS is a tough, rigid thermoplastic with good impact resistance and is easily molded. It is widely used in automotive, appliance, and consumer electronics applications.
  • Polyamide (Nylon): Nylon is a high-strength thermoplastic with good chemical resistance and excellent wear properties. It is usually used in bearings, gears, and electrical connectors.
  • Polystyrene (PS): PS is a lightweight and rigid thermoplastic that is often used in consumer goods, packaging, and medical applications.

2.Engineering Plastics:

  • Polyethylene Terephthalate (PET): PET is a strong, lightweight, transparent engineering plastic with good chemical resistance and dimensional stability. It is commonly used in packaging, electrical connectors, and mechanical components.
  • Polybutylene Terephthalate (PBT): PBT is a thermoplastic with excellent electrical properties, chemical resistance, and dimensional stability. It is often used in automotive, electrical, and appliance applications.
  • Polyphenylene Sulfide (PPS): PPS is a high-performance thermoplastic with excellent chemical resistance, dimensional stability, and heat resistance. It is commonly used in automotive, electrical, and industrial applications.


  • Thermoplastic Elastomers: TPEs are a family of elastomeric materials that combine plastics' processing advantages with rubber's flexibility and elasticity. They are often used in applications that require soft-touch surfaces, seals, gaskets, and grips.

These are just a few examples of materials used for insert molding. The material selection depends on factors such as the specific application requirements, desired mechanical properties, chemical resistance, temperature resistance, and regulatory considerations. It is essential to consult with material suppliers or experts to determine the most suitable material for a given insert molding application.

A: Several common methods are used to place inserts in the mold during insert molding. The choice of method is decided by factors such as the design of the part, the type of insert, and the level of automation required. Here are some placement methods:

  1. Manual Placement:
  • Manual Insertion: In this method, operators manually place the inserts into the mold cavities before the injection molding process begins. This method is suitable for low-volume production or when the inserts require precise positioning or orientation.
  1. Semi-Automatic Placement:
  • Fixture-Based Placement: Inserts are placed in a fixture or carrier that positions them accurately within the mold cavities. The fixture is manually or mechanically loaded into the mold, ensuring consistent placement. This method improves efficiency and reduces operator error.
  1. Automatic Placement:
  • Robotic Insert Placement: Industrial robots equipped with grippers or specialized end-of-arm tools (EOAT) are used to pick and place inserts into the mold cavities. Robotic systems offer precise and repeatable insert placement and high-speed operation and can be integrated into the molding process for increased automation.
  1. Overmolding:
  • Overmolding involves placing the insert into the mold cavity and then injecting the molten plastic material over it, encapsulating the insert. The insert is typically pre-positioned or fixtured in the mold to ensure proper positioning. Overmolding is commonly used for applications requiring a combination of materials or when additional features or functionality are desired.

It's important to note that the specific placement method may vary depending on the part's complexity, the size and weight of the inserts, and the molding process requirements. Design considerations such as the presence of undercuts, the need for proper venting, and the ability to achieve consistent insert positioning should also be considered when selecting the appropriate placement method.

A: While insert molding offers numerous advantages, there are also some potential disadvantages to consider. Here are a few:

  1. Higher initial costs: Insert molding often requires additional equipment, such as insert placement fixtures or robotic systems, which can increase the initial investment cost compared to traditional molding processes.
  2. Design limitations: The design of the part may be constrained by the presence of inserts. Factors such as the inserts' size, shape, and location need to be carefully considered to ensure proper moldability and functionality.
  3. Insert Compatibility: The choice of inserts is critical for successful insert molding. Some inserts may not be compatible with the molding material or process conditions, leading to issues such as poor adhesion, inadequate bonding, or insert deformation during molding.
  4. Insert displacement: During the injection molding process, the inserts may experience displacement or movement due to the pressure and flow of the molten material. This can result in misalignment or improper positioning of the inserts, affecting the final part quality.
  5. Increased cycle time: Insert molding can improve the cycle time compared to traditional molding processes. The additional steps involved in insert placement, such as manual or robotic handling, can add time to the overall production process.
  6. Limited design changes: Once the inserts are placed, and the mold is set, making design changes or replacing inserts can be challenging and time-consuming. This can limit the flexibility for design modifications during the production process.

It's important to note that these disadvantages could be mitigated or minimized through careful design considerations, proper material selection, and process optimization. Working closely with experienced mold designers, material suppliers, and insert molding experts can help address these challenges and maximize the benefits of insert molding.

A: Designing for insert molding involves considering several key elements to ensure the successful integration of the inserts with the molded part. Here are some important design considerations:

  1. Insert Selection: Choose inserts that are compatible with the molding material and process conditions. Consider factors such as material compatibility, adhesion properties, thermal expansion coefficients, and mechanical properties to ensure proper bonding and functionality.
  2. Insert Placement: Determine the optimal location and orientation of the inserts within the mold cavity. Consider factors such as part geometry, functional requirements, and ease of insert placement. Properly positioning the inserts helps achieve consistent and accurate placement during molding.
  3. Undercuts and Overmolding: If the design includes undercuts or overmolding features, ensure that the mold design allows for the proper flow of the molten material around the inserts. Consider features like draft angles, side actions, or lifters to facilitate the ejection of the part from the mold.
  4. Venting: Proper venting is crucial to avoid trapping air or gases during molding. Design the mold with adequate venting channels to allow air to escape and prevent defects like voids or burn marks around the inserts.
  5. Stress Concentration: Minimize stress concentrations around the inserts by incorporating fillets or radii at the junctions between the inserts and the molded material. This helps distribute stress evenly and reduces the likelihood of stress-related failures.
  6. Part Thickness and Wall Thickness Transitions: Ensure uniform part thickness around the inserts to avoid variations in cooling rates and potential warpage or shrinkage issues. Gradual transitions in wall thickness help maintain structural integrity and minimize stress concentrations.
  7. Gate Placement: Carefully consider the location of the gates, which are the entry points for the molten material into the mold cavity. Place the gates in a way that optimizes flow paths and minimizes the risk of damaging or displacing the inserts during injection.
  8. Ejection and Demolding: Design the mold with appropriate ejection mechanisms to facilitate the removal of the part from the mold without damaging the inserts. Consider features like ejector pins, air ejection, or specialized demolding tools to ensure smooth and efficient part release.

By considering these design elements, it is possible to optimize the insert molding process, enhance part quality, and maximize the benefits of integrating inserts into the molded part. Working with experienced mold designers and insert molding specialists provides valuable insight and guidance throughout the design process.

A: When injecting inserts, several common methods exist for embedding nuts or other threaded inserts into the molded part. Here are a few embedding methods:

  1. Heat Staking: This method involves pressing the insert into a pre-molded hole or boss in the part. The heat softens the surrounding plastic, allowing the insert to be embedded. Once the plastic cools and hardens, it securely holds the insert in place. Heat staking is commonly used for thermoplastics.
  2. Mold-In Method: The insert is placed in the mold cavity before the injection molding process begins. As the molten plastic fills the mold, it flows around the insert, encapsulating and securing it within the part. This method works with blades of all shapes and sizes.
  3. Ultrasonic Insertion: Ultrasonic energy is used to vibrate the insert, generating frictional heat that melts and embeds the insert into the plastic. The ultrasonic method is suitable for thermoplastics and is often used for smaller inserts or when precise control over the insert depth is required.
  4. Cold Press-In: This method involves manually or mechanically pressing the insert into a pre-molded hole in the part after the molding process. The insert is typically knurled or has undercuts to provide mechanical interlocking with the plastic. Cold press-in is commonly used for softer materials or inserts with specialized features.

The embedding method selection depends on factors such as the material being molded, the size and shape of the insert, the required insert retention strength, and the production volume. It's essential to consult with mold designers, material suppliers, or insert molding experts to determine the most suitable embedding method for your specific application.

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