Cost is a significant factor when deciding between manufacturing processes, such as CNC vs cast. These two methods have their advantages depending on your project needs. However, they may suit the manufacturing of the same materials, especially when such a project does not have specific stringent requirements.
Therefore, the cost implications of either process may prove vital in determining which manufacturer is the best fit for such a project. This article discusses both processes and informs you whether die casting is cheaper than CNC machining. It examines factors like production volume, material waste, and part complexity that may have cost implications during manufacturing.
Die Casting vs CNC Machining: A Brief Overview
Die casting and CNC machining are popular manufacturing processes for creating metal parts and structures. However, their modes of operation differ significantly.
Die casting is a versatile and efficient metal casting process used to produce high-quality parts. It offers good precision quality, making it ideal in industries like automotive. This manufacturing technique uses high pressure to force molten metal into a mold or die, where it cools and hardens to form the desired shape. It is primarily used for large production and complex geometries while maintaining tight tolerances.
On the other hand, CNC machining is a subtractive process; therefore, it involves removing materials from a solid block. However, its operation is computer-controlled, ensuring seamless cutting of the workpiece until the desired shape is achieved. Depending on the project, CNC machining can create parts from various metals and plastics using multiple devices, such as mills, lathes, routers, and grinders.
The desired cuts are programmed into the software, which dictates cutting motion and other machining parameters to the corresponding machines and tools. This method is particularly useful in producing parts with very high precision. In addition, it suits bulk-volume and low-scale manufacturing services.
Is Die Casting Cheaper Than Machining
We can’t answer yes or no because several factors influence the cost of die casting and CNC machining services. Many consider die casting the cheaper process because of its less complexity and cheaper machine cost; however, some factors may influence the cost of either process. Still, factors such as part complexity, production volume, and desired precision level may influence the manufacturing cost.
Below is a breakdown of how die casting and CNC machining may differ in cost.
Initial Setup Costs
The initial setup cost in die casting involves the cost of the machine and mold creation, while for CNC machining, it refers to the device’s price. Indeed, CNC machines are more expensive than die-casting machines. However, the extra cost incurred due to mold creation may offset die casting expenses. Therefore, the initial cost of die casting may be on par, if not even higher than CNC machining, especially for low-volume complex fabrication.
Production Volume
Die casting is more economical when produced on a large scale. In contrast, CNC machining is ideal for both low—and high-scale manufacturing, and as mentioned above, it may be even cheaper for low-scale. However, die casting becomes cheaper when created in bulk, as precision manufacturing companies utilize the same mold, ensuring the cost-per-unit price is more affordable. However, the cost per part also decreases for bulk volume CNC machined components, but not as low as in die casting, making the atter cheaper.
Material Waste
In terms of material waste, die casting produces little waste because the molten metal is poured into a precise mold to form parts, leaving little or no scrap metal. In contrast, CNC machining is a subtractive process; it essentially involves cutting away materials until the desired shape is achieved. The more complex a part is, the more waste it is likely to generate when using CNC machining. Moreover, leftovers from die casting may be recycled and reused for further casting, generating minimal waste.
Part Complexity and Precision
CNC machining is more suitable when dealing with parts that require extremely high tolerances and intricate designs. Although die casting can produce complicated designs, it may struggle with parts requiring tight tolerances and complex internal geometries. Such fabrications always increase the risk of surface defects like burrs and flashes, requiring extra cost to correct.
Manufacturers may even use machining services to achieve high-precision standards of already casted parts. Therefore, CNC machining may be more cost-effective for complex fabrications because of its higher precision and accuracy, limiting the need for post-processing.
Die Casting vs CNC Machining: Which is Cheaper
Thus far, we have shown that the cost of die casting and CNC machining may vary depending on the project requirements. Therefore, manufacturers and OEMs may need to carefully examine their projects’ specifications before concluding on the cheaper option.
This section will examine the cost implication of die casting in relation to CNC in three categories.
High-Volume Production
When manufacturers are producing in large quantities, die casting is known to be the cheaper option. The high cost of making the die or mold becomes insignificant as the molds will be used to run multiple productions at high speed with the need for minimal labor. As production volume increases, the cost per part cost of the die casting drops significantly.
Low-volume or Prototype Production
CNC machining is often the more economical choice when production is low-volume or during prototype creation. The cost of set-up for CNC machining is the cost-determining factor of the process. Unlike die casting, which requires a tailored die or mold cavity to suit the intended project, CNC does not require sophisticated tooling besides cutting tools. Therefore, while the part per price is high, the fact that there is no need to overspend on producing die makes CNC a cost-effective option for low-volume production and prototypes.
For Complex or High-Precision Parts
Although die casting is known to offer good precision, it may not be applicable when extreme precision and intricate designs are considered. Manufacturers and OEMs often need to engage in other expensive post-finishes, which may even include machining, to attain high precision and tolerance standards. On the other hand, CNC machines are known to achieve very tight tolerances and produce parts with complex internal geometries that may be difficult to replicate using die casting.
Conclusion
When cost is considered, deciding which is more economical, CNC machining or die casting, depends highly on the project type. The manufacturer should also carefully consider factors like production volume, material choice, and part complexity to determine which process is more cost-effective for their needs.
Die casting is typically cheaper for high-volume runs because the cost of producing a single die will spread across the quantity being produced, while CNC casting is cheaper when producing prototypes or low-volume runs. When the project types also include highly complex geometries or materials requiring very high tolerances, it is more economical to adopt CNC machining.
