Understanding Precision Die Casting

Understanding Precision Die Casting

In comparison to manufacturing processes such as machining and stamping, die casting offers significant advantages that lead to greater cost savings. With precision die casting, near net shapes and other features such as minimal draft angles can be attained, thus minimising secondary operations such as trimming and machining. However, as with any manufacturing process, it is vital to find out more before deciding which process is the most suitable for your components’ requirements.

Here are some of the most frequently asked questions about precision die casting:

Why is Precision Die Casting better than CNC Machining?

Precision die casting is much faster than CNC machining and is a process that can be repeated easily. Consider this, the time taken to machine a detailed part from a solid metal piece will definitely take more time than machining a post-cast piece to further fine tune it. Thus, with precision die casting, production speed is greatly improved upon. Additionally, with faster production speed comes the reduction of overall cost per piece of casting as well as the capacity to produce in larger volumes. 

Another plus point that was mentioned earlier is the fact that some die cast tools (using the multi slide die casting process), are able to ensure the complex geometry of the product’s design. Some of these complex geometrical factors include near net shapes and minimal draft angles. This is why fewer secondary operations associated with precision die casting exist, as compared to other manufacturing processes. With precision die casting, you can cast complex geometries that would otherwise need to be manufactured from two or more pieces and assembled via other production methods. 

Is Precision Die Casting Really More Effective?

The effectiveness of precision die casting should be considered on a case-by-case basis. There are scenarios in which CNC Machining can be faster than precision die casting, one of which being a faster lead time (small volume production). However a digital model is required. All things considered, converting to precision die casting from CNC Machining as mentioned earlier, results in minimal secondary operations, better part performance, and better cost at high volume production. 

Which Die Cast Metals to Use and Produce?

The range of die cast metals we use at EKO Industries consists of Aluminium and Zinc.

In terms of production, Aluminium is 100% recyclable, and has no deterioration in properties, thus it can serve the same applications with the same level of performance as primary Aluminium extracted from Bauxite. Aluminium is light and strong, making it ideal for applications where these properties are required. The automotive industry is one of the largest users of Aluminium die casting components..

As for Zinc, just like Aluminium it is versatile and easy to cast, and is also widely used to custom parts and components for different industrial applications – such as electronic devices, fuel systems, and more. Zinc also responds exceptionally well to the moulding process. When it comes to flexibility, Zinc is more malleable than Aluminium. For very complex shapes or tight tolerances, Zinc die casting might be a better option.

What is the Minimum Wall Thickness for Die Cast Parts?

The minimum wall thickness attainable boils down to the part’s geometry and design, but in an ideal scenario, walls can be produced as thin as 0.3mm. To maintain high strength, a minimum wall thickness of 0.5mm – 1.0mm is required.  

What is the Tightest Tolerance Attainable?

Just like wall thickness, tolerance is dependent on the part’s geometry. For exact tolerances, the figure is generally between ±0.002” to ±0.004” for Aluminium, while Zinc can hold between ±0.001” to ±0.002”. Although a tolerance of ±0.001” is possible, manufacturers ought to avoid having unnecessary costs added into their designs. When exact tolerances and minimal draft angles are requested for when they are not required to maximise part performance, such castings fail. What manufacturers should do is determine what is critical and what is not and provide allowance for more lenient tolerance zones. This will help extend your part’s lifespan as there are fewer exact geometries being subjected to wear and tear. Various tolerance zones also collectively help your component avoid secondary operations wherever possible, allowing you to get the most out of your design during its die casting process.

What are the Available Cosmetic and Protective Surface Finishes 

For cosmetic purposes, corrosion protection, or sealing surface porosity, surface treatments are offered to die cast components. Some of these treatments include:

  • Anodising – A cost-friendly, corrosion-resistant, durable, and non-conductive protective coating that seals the part. It exists in various colours and is one of the most environmentally friendly coating industry processes as it does not produce any hazardous waste.
  • Powder Coating – A dry coating process used as a metal finish, mostly on industrial equipment. It is available in different gloss levels, textures, colours, and can be useful on different surfaces. 
  • E-Coating – A process that uses electricity to attract the paint product to a metal surface. It is often used on its own since it gives excellent coverage but can also be useful as an undercoat for other coatings such as a powder coat.
  • Impregnation – A great option to use after machining to remove the “skin” of the casting to create a leak-free component, seal porosity, and create watertight components. Since impregnation prevents leakages, it can be used in plumbing for water pipes or through automotive die casting to fix engine parts.

Choose EKO for Your Precision Die Casting Needs

With over 20 years of experience, EKO Industries consistently delivers value through our expertise in die cast engineering as well as efficiency in our operations. If you are interested to learn more about our precision die casting process or some of our other manufacturing capabilities, contact us to find out more.

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