Die Casting vs. Injection Molding

Manufacturers compare die casting vs. injection molding when considering various production techniques for their projects. These two methods are the most used manufacturing processes in multiple industries. While these processes have similarities, they also have differences, which you should factor into your fabrication and production process.


In this discussion, we’ll cover die casting vs. injection molding, the processes involved in each method, their advantages, and other essential details. It is best to consider these factors when choosing the production method that best suits your products.


What is the Die Casting Process?


When using the die-casting process, fabricators inject molten metal into a steel die. This method is performed under extreme pressure, which results in increased repeatability and improved dimensional accuracy during manufacturing. Any excess material is removed using various methods, such as employing ejector pins, which depend on the design and shape of the part being manufactured.

This process isn’t new since it has been used since the mid-19th century. Since this manufacturing method calls for the use of molten metals, it is best suited for making products with complex geometric parts. Die casting is also highly recommended for manufacturing products and components made from non-ferrous metals, such as copper, zinc, and aluminum.


Die Casting Advantages and Disadvantages


If you want to create products with an excellent surface finish, die casting is the better option. Since the parts produced in this process solidify under extreme pressure, they tend to feature superior strength and durability. The finished pieces can also be painted and polished according to your specifications. In addition, die casting allows you to produce more parts quickly, which is preferred if you are producing en masse.


Die Casting Pros

  • Allows for seamless and rapid production
  • Best suited for geometrically complex parts
  • Produces highly durable components and products
  • Highly replicable process
  • Produces excellent surface finish


  • Limited to metals with low melting points
  • It can lead to metal porosity if the process isn’t performed with all necessary precautions
  • Not ideal for manufacturing large parts
  • It may cost more for small-scale production

What is the Injection Molding Process?


You will find that the processes are almost similar when you compare die casting vs. injection molding. These processes begin with a die or mold preparation, filled with material allowed to cool while in the mold or die. After cooling, the produced materials are ejected and used for other manufacturing processes.


The difference between these two manufacturing processes is in the material used. The die-casting process uses metal, while injection molding is best suited for thermoplastics. Injection molding allows for the creation of complex plastic parts and components. It is best suited for manufacturing products made from various polymers and similar materials, such as polypropylene (PP), polystyrene (PS), nylon, and acrylonitrile butadiene styrene (ABS).


Injection Molding Advantages and Disadvantages


Just like the die-casting process, injection molding has pros and cons. Since the production process is done in a tightly controlled automated environment, it can be used to make parts and products with consistency. The parts produced using this process require less secondary finishing. In addition, injection molding is best suited for manufacturing solid and lightweight components.


Injection Molding Pros

  • It requires less labor
  • Almost zero waste materials are produced
  • Fast manufacturing process, which allows you to produce in high volume
  • Efficient production with high-quality output
  • They have very flexible options and can work well with various polymers, resins, and plastics



  • Lengthy setup time required for the preparation of the equipment
  • You may have to purchase additional equipment depending on their project
  • Requires specific precautions to ensure the quality of your parts

Comparing Injection Molding and Die Casting


Apart from the materials used, there are other verifiable differences when you compare die casting vs. injection molding. These processes vary in capabilities, tolerances, precision, surface finishing, cost, and applications.


1. Materials Used

As mentioned earlier, die casting uses molten metals. In contrast, injection molding can be used for polymers, resins, and plastics. It is also important to note that newer injection molding processes exist where different alloys, such as aluminum and steel, can be used as raw materials. This feature shows that injection molding can be a broader process that allows the use of more types of raw materials.


2. Complexity and Design Considerations

Die-casted materials exhibit higher tolerances and better precision, allowing for more complex parts to be produced. This feature is beneficial when manufacturing more complex parts and designs. Die casting is better suited for manufacturing products with more detailed components.


3. Surface Finish and Cosmetic Requirements

The final die-casting products already have a finer surface finish after ejection from the die. However, extra finishing can be performed for die-casting and injection molding parts and products.


Surface finishings for die-casted parts include impregnation, gold plating, chem film, powder coating, and anodizing. On the other hand, surface finishing options for injection molding include decorating, cleaning, deflating, and delegating. These finishing processes help achieve the cosmetic requirements for your products, enhancing their chemical and mechanical resistance, thickness, and durability.


4. Cost Factors

The cost factors for die casting mainly fall under labor and equipment. Steel components can lose acuity due to die erosion, requiring some labor to correct, which increases your tooling costs. Injection molding, on the other hand, tends to be more affordable since it is less labor-intensive. Cost factors include raw materials and the complexity of the parts you intend to produce.


Potential Industries and Applications


Die casting is best suited for fabricating small to medium-sized parts for various commercial products, including gears, sinks, automobiles, and bathroom and plumbing equipment. Injection molding, on the other hand, can be used to produce larger parts and plastic products. It can manufacture plastic products, including kids’ toys, plastic tables, mechanical parts, hair combs, and other everyday items.


Which Fabrication Method to Use?


When choosing between die casting and injection molding, you should consider the material, labor costs, the complexity of your design, your budget, and the aesthetic requirements of your products. 


All-Plastics offers the latest injection molding technology. Our processes allow us to manufacture products in a zero-defect environment. We improve your production efficiency while producing precise, complex designs according to your specifications. Please fill out our online contact form to request a quote or ask a question.