How to Calculate Die Casting Cost?

Die casting is a widely used manufacturing process, particularly in the automotive, aerospace, and energy industries. Despite its popularity, the cost of die casting is a significant concern for many businesses. Understanding how to optimize die casting costs is crucial before you can fully benefit from its advantages, such as high dimensional accuracy, suitability for complex parts, use of recyclable materials, and fast production times. This article will discuss die casting costs, the factors that influence them, and strategies for optimization.

Is Die Casting Costly?

Yes, die casting can be expensive, especially when producing a small number of parts. The high costs often overshadow the process's advantages, making it a less viable option for low-volume production. However, for large-scale manufacturing, die casting becomes more cost-effective. The primary factors contributing to the high cost of die casting include:

1. Material Cost

Materials are a significant factor in die casting costs, as they determine the type of mold, the casting process, and the quality of the final product. The material's weight, volume, density, and unit price all influence the overall cost.

For instance, aluminum is a popular choice due to its quality, but it comes with a higher price tag. The cost of materials can rise if they are rare or require specialized processes. For example, aluminum requires a cold chamber die casting process, which is more costly.

• Raw Material Cost: This is the cost of the metal used for die casting. The most common materials include aluminum, zinc, magnesium, and copper.

  • Calculation: Material Cost=Weight of the Part×Cost per Unit Weight of the Material
  • Consider the scrap rate or material wastage, typically around 5-10%.

• Additional Material Costs: Include the cost of any coatings, surface treatments, or inserts used in the casting.
  
  

2. Production Costs

Production costs are interrelated with machine type and labor. Large parts require machines with greater clamping force, leading to higher machine costs. Some materials with higher flow rates also require more expensive, high-tonnage machines.

Production costs can be optimized by reducing cycle time (including injection, cooling, and reset times) and minimizing the part’s wall thickness.

• Machine Costs: This includes the cost of operating the die casting machine, which depends on machine size, cycle time, and hourly rate.

  • Calculation: Machine Cost=Cycle Time per Part×Hourly Machine Rate
  • Multiply by the number of parts produced to get the total machine cost.

• Labor Costs: The cost of labor required to operate the machine and perform secondary operations.

  • Calculation: Labor Cost=Time per Part×Hourly Labor Rate

• Energy Costs: Electricity and other utilities consumed during the process.

  • Calculation: Energy Cost=Machine Power Consumption×Operating Time×Cost per kWh

• Post-Processing Costs: Include trimming, deburring, machining, and finishing operations.

  • Calculation: Post-Processing Cost=Time per Part×Hourly Rate for Post-Processing

3. Tooling Costs

Tooling is another major contributor to die casting costs. Complex designs and large parts require molds with high dimensional tolerance, which drives up costs. The cost of tooling is particularly high for molds designed for large-scale production, as these require durable materials to ensure longevity.

Die Cost: The cost of manufacturing the die, including design, materials, and fabrication.

• Calculation:
• Tooling Cost per Part=Total Die Cost / Expected Number of Parts from the DieTotal Die Cost​
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• Factor in the die maintenance cost over its lifespan.

4. Overhead Costs

• Factory Overhead: Costs related to the facility, including rent, utilities, and administrative expenses.

  • Calculation: Overhead Cost per Part=Total Overhead Cost / Total Number of Parts Produced in the Period​

• Shipping and Packaging Costs: Costs for packaging the parts and shipping them to the customer.

  • Calculation: Shipping and Packaging Cost=Packaging Material Cost+Shipping Rate

5. Total Cost Calculation

• Add up all the individual costs to get the total cost per part.
  • Formula: Total Cost per Part=Material Cost+Machine Cost+Labor Cost+Energy Cost+Post-Processing Cost+Tooling Cost per Part+Overhead Cost per Part+Shipping and Packaging Cost

6. Profit Margin

• After calculating the total cost per part, add your desired profit margin to determine the final price.
  • Calculation: Final Price per Part=Total Cost per Part × (1+Profit Margin)

By following these steps, you can estimate the die casting cost for your specific project.

Die Casting Mold Costs and How to Reduce Them

The die casting mold, which shapes the final product, is a significant cost factor. Material selection and design complexity play a crucial role in determining mold costs. Here’s how you can manage these costs:

1. Die Cast Mold Design

A simpler design generally reduces costs, but the design must still meet project requirements. For complex products, you may need a mold with a sophisticated design and manufacturing process to ensure accuracy and quality. While CNC machining is often preferred for its precision, it adds to the overall cost. Optimizing the design to use less material, such as thinner walls, can help lower costs.

2. Use Multi-Cavity Molds

Using a mold with multiple cavities can reduce costs, especially for small parts. For instance, a mold with two to six cavities can significantly cut down on production costs.

3. Material Used in Making the Mold

The material used for the mold must align with the casting requirements and production volume. Larger castings require more robust molds, which means higher material costs. However, for large-scale production, investing in a higher-quality material for the mold can be more cost-effective in the long run.

4. Proper Tooling Maintenance

Maintaining the mold properly can extend its life and reduce costs associated with creating new molds. Regular maintenance includes predicting mold longevity, drafting maintenance procedures, cleaning with compatible materials, and storing the mold in optimal conditions.

Die Casting Process Costs

Optimizing the die casting process itself can also lead to cost savings. The two main areas to focus on are the type of machine used and labor costs.

1. Die Casting Machine Costs

The type of machine—hot chamber or cold chamber—affects costs significantly. Cold chamber machines are more expensive due to their sophistication, which is necessary for handling materials like aluminum and magnesium. The extra steps involved in cold chamber casting result in slower production times and higher costs due to increased oxidation and the need for surface finishing.

2. Labor Costs

Labor costs can vary depending on the level of automation. Reducing setup labor costs can be achieved by working with established die casting services, while direct labor costs can be minimized by automating the process.

Finishing Costs

Finishing processes add to the overall cost but are essential for achieving the desired durability, protection, and aesthetics of the final product. Common finishing options include painting, plating, antiquing, and ceramic coating, each with its associated costs.

By understanding and managing these factors, businesses can better estimate and optimize die casting costs, making it a more viable option for large-scale production.