In producing complex parts, both CNC machining and die-casting processes present some value propositions. However, consider certain aspects in selecting a suitable process for the project. These may be the material requirements, production rate, and cost, among others. So, this guide will also aim to provide an overview on the major differences between die-casting vs CNC machining. It will also discuss their advantages and disadvantages, and what needs to be considered when choosing between CNC machining and die casting.
What is CNC Machining?
CNC (Computer Numerical Control) machining is a form of production known as subtractive manufacturing, i.e. the elimination of material from a block of metal. This elimination is generally called a piece to form a finished part with specific geometry. It includes cutting materials into the desired shape with the help of computer-controlled machines. These machines can be Mills, Lathes, and routers. CNC or computer numerical control machining is highly valued for its accuracy, versatility, and versatility in material choice, including metals, plastics, and composites.
What is Die Casting?
The die-casting process involves injecting fluid material into a mold cavity through applying high pressure. The mold generally fabricated from steel enables the formation of parts that are intricate in form and with excellent features. After the metal has cooled down and has gained its solidity the part is then expelled from the mold. It is used where large quantities of the same metal part like nonferrous metals are being manufactured. These materials can be aluminum, zinc, and magnesium.
Key Factors for Choosing Between CNC Machining or Die Casting
Here are some key factors we know for selecting between CNC machining and Die-casting.
- Material Requirements: CNC machining can work with a very broad range of materials. While die casting can only be used on specific metals.
- Production Volume: When it comes to the type of production die casting is cheap in the production of large quantities of products as compared to CNC machining. So, it is quite advantageous for small quantities of production.
- Part Complexity: CNC machining is the most preferable for detailed designs. While die casting is perfectly suitable for complex shapes and small details.
- Lead Time: Compared to traditional machining, CNC machining usually has a smaller lead time. So, it is ideal for creating prototypes or small production runs.
- Cost: The advantage of die casting is that it offers more economic value in the case of larger production runs. However, the cost of tooling is high in this process. On the other hand, CNC machining is more cost-effective at the initial stages of production than at the latter stages of production.
How does CNC Machining Work?
CNC machining means Computer Numerical Control machining and is a subtraction process in which a machine is used to direct a tool, which cuts a part out of a block of material. It is an electronic machine that keeps the correct shape of the design while cutting. Besides this, it helps shape as well as polish the material. This method is very precise and can be used on a whole range of substrates from aluminum and other metals to plastics.
How does Die Casting Work?
Die casting is where metal is forced under pressure into a mold that forms from steel. The equipment and the material used are mechanical. They first cool and then solidify into the shape of the mold as per the desired requirement thus achieving a high degree of accuracy. Besides this, it is most suitable for manufacturing a large quantity of intricate metal parts or relatively soft metals such as aluminum, zinc, and magnesium.
What are the Differences Between Die Casting vs CNC Machining?
The following are the major aspects to differentiate between Die-casting and CNC machining.
1. Process Type
Die casting is a short-cycle process of making metals into shapes of the required design by pouring molten metal into a mold. CNC is the other category of machining. It is subtractive for a solid block material is cut away using tools controlled by computers, It gives highly accurate results and is good for complex shapes.
2. Material Compatibility
Die casting involves working with non-ferrous metals such as aluminum, zinc, and magnesium. On the other hand, CNC machining uses a wider range of materials, i.e. metals, plastics, and composites. So, it shows flexibility in material selection.
3. Production Volume
Die casting tends to be more economical in the creation of large numbers of items. Here, the cost per part is considerably cheaper when the die mold is made. CNC machining applies to low to medium volumes so they’re ideal for quick and easy changes than larger runs.
4. Part Complexity
As for die casting, it enables the creation of different shapes with high detail in the final part of one cycle. Thus it is suitable for application in large quantities. CNC machining offers excellent accuracy and is highly suitable for creating complicated shapes. Moreover, simple shapes can be built in a single step in the CNC machining process.
5. Lead Time and Setup
Die casting has relatively longer initial lead times especially due to mold making. Here, the production times are relatively fast after mold manufacturing. Another reason for the wide use of CNC machining is the short lead times and relatively quick changes than other conventional machining methods.
6. Cost Considerations
Die-casting aluminum has considerable fixed costs intact. However, it operates at a low cost per unit in large numbers. CNC machining is cheaper in the long run but may be costly for single-part production. It takes a longer time to produce parts than the cast aluminum process. So, it is suitable for small-volume or precision-requiring projects.
This table will briefly describe the Die casting vs CNC machining. So, you can get a better understanding of their differences concerning different aspects.
| Aspect | Die Casting | CNC Machining |
| Process Type | Here the molten metal is injected into a steel mold.
|
Material removed from a solid block using CNC tools. |
| Material Compatibility | Non-ferrous metals (aluminum, zinc, magnesium). | Metals (aluminum, steel, titanium), plastics, composites. |
| Production Volume | Economical for high volumes (e.g., 10,000 to 1 million parts). | Suitable for low to medium volumes (e.g., 1 to 1,000 parts). |
| Part Complexity | Handles complex shapes and fine details effectively. | High precision for intricate designs; multiple setups may be needed. |
| Lead Time and Setup | Mold creation takes 4-12 weeks; fast production cycle (e.g., 10-30 seconds per part). | Setup time typically 1-5 days; faster production for small batches (e.g., 1-20 parts per hour). |
| Cost Considerations | High initial tooling costs ($5,000 to $50,000+); low cost per part ($0.10 to $5.00 per part). | Lower initial cost; higher per-part cost ($1 to $100+ depending on complexity). |
Advantages and Disadvantages of CNC Machining
The following are the pros and cons of CNC Machining. These will help us understand how CNC machining is better for our projects and its limitations.
Pros:
- High precision and accuracy.
- It can be used with many different materials and many colors.
- Applicable for firms that produce moderate levels of units with low to medium variability.
- Faster time to deploy and lower lead time.
- Flexibility in design modifications.
Cons:
- This process consumes a lot of materials to arrive at the final product. Therefore, it leads to wastage.
- Different cost structures for mass production are based on the total cost per part in a mass-production operation. This cost is higher for a large number of operations performed.
- Of course, working extra hours on complicated parts is another critical issue to consider in machining.
- If the tool is only used and the technique is not implemented in the existing machines. It is limited to the tool’s mobility.
- Geometries that involve hatchings and other such structures, may need several operations to be completed.
Advantages and Disadvantages of Die Casting
The following are the pros and cons of die-casting:
Pros:
- Cost-effective for high-volume production.
- High detail and the possibility to make complicated forms, due to thin walls.
- No need for re-shaping which reduces the use of more material than required.
- It lengthened the life of cast parts making it possible to achieve high strength.
- High and uniform dimension accuracy, along with fabrication accuracy.
Cons:
- High initial tooling costs.
- These limitations apply only to several metals and alloys.
- Therefore, longer lead times are expected to be inevitable when it comes to the development of tooling.
- Not very useful for small-batch production.
- Some features of the castings that may be attained with sand casting method: Potential for porosity and other casting defects.
Which Process is More Appropriate for My Project?
For a given project, you can choose between CNC machining and die casting depending on what will suit the project best. If you require high precision parts, low volumes, or require materials that cannot be used in die casting. So, you can opt for CNC machining as it is suitable for use. On the other hand, if you are making large iron machined parts with small features. Then die casting can prove to be more economical and effective.
Applications of CNC Machining
- Aerospace components
- Automotive parts
- Medical devices
- Precision tools
- Electronics housings
- Custom prototypes
- Industrial machinery parts
Applications of Die Casting
- Automotive engine components
- Consumer electronics casings
- Hardware tools
- Household appliance parts
- Telecommunications equipment
- Lighting fixtures
- Industrial machinery components
Conclusion
In conclusion, CNC machining and die casting are two distinct manufacturing procedures. They both need to be compared based on certain factors including material type, parts quantity that you want to produce, complexity of the part, and price. Besides this, each of the two processes has its strengths and weaknesses. So, we know these will help determine which method to adopt in the manufacturing process.
Frequently Asked Questions
Q1. What can be fabricated in CNC?
CNC machining can manipulate a lot of materials such as metal, plastic, composite, and even wood.
Q2. Is die casting appropriate for making small quantities of parts?
Absolutely yes. Die casting is more suitable for large production since it requires high initial costs for tool preparation.
Q3. Is it possible to create parts with complicated shapes using CNC machining?
Yes, the machining done with the use of a computer can create such small designs. But it may require more than one process.
Q4. What are the main benefits of die-casting?
It is suitable to manufacture parts in a large number of pieces. These pieces have uniform quality and small intricate features.
Q5. What is the difference between lead times for cnc machining and die casting?
CNC machining normally takes a shorter time than die casting. Therefore, it is preferable for prototype runs and limited production quantities.
