Design for Manufacturability (DFM) Tips for Die Cast Parts

Die casting can be a tricky thing to master. That’s why at JINGXIN, our experts are here helping through every phase of the process. JINGXIN is constantly working to provide uncommon solutions to customers, and one example is the extensive product design assistance we offer.

We work with our customers on the design of their castings to incorporate features that will maintain functionality while optimizing features that enable the casting to be easier to produce. This allows our customers to receive a casting from JINXIN that is designed to minimize their cost while allowing JINGXIN to minimize our production costs.

Customers often know what they want functionally and we know how to make a casting that will meet those needs. Here are our top thirteen tips that can help you understand our process and the reasoning behind the design guidance we provide.

Die Casting Design Tips:

1. Die Casting Parts Weight Reduction

The goal is to reduce the volume of material for components in order to save cost and weight in die casting. The more metal the component contains, the more time it will take to fill the die cavity and to cool the metal prior to ejection. We can design pockets to make the cross section thinner, and use ribs to strengthen if necessary. The locations of pockets need to be considered carefully, as they can sometimes cause non-constant shrinkage, which may affect components’ accuracy.

Die Casting Design Tips

2. Adding Ribs to Die Casting Parts

The designer can add ribs on thin walls die casting to increase component strength. In particular, he will need to locate the ribs on suitable locations for ejector pins and to assist in metal flow. If possible, the ribs should include fillets and radii as much as possible to reduce sharp corners and rapid changes in cross sections.

3. Die Casting Parts Shrinkage

All metals will shrink from die casting temperature to room temperature. The theoretical shrinkage is about 0.6%, always toward the nominal center as shown in the picture to the right. The shrinkage permits the casting to escape from the tooling cavity, but tends to lock it onto any die section that projects into it. The designer can apply draft into the component to reduce shrinkage.

Die Casting Design Tips

4. Draft in Die Casting

Draft is the small taper on the cavity sides that helps the die casting component to eject. Surface with draft on it usually is highly polished. The outer gap will increase 0.017mm per 1mm based on 1 degree. If no draft is provided the caster has to use some tolerance for draft.

5. Uniform Die Casting Parts Cross Sections

Designer can make the cross sections uniform in order to speed up the metal flow through the die. Otherwise the sudden wall thickness change will cause turbulence in the die cast metal, and result in porosity. Furthermore, casting with large difference in cross sections will shrink irregularly.

6. Radii and Fillets in Die Casting Parts

Designer has to avoid sharp corners and rapid change in cross sections. In addition, an inside corner should be designed with a fillet and the outside corner with a radius as much as possible. Reducing sharp inside corners can give additional strength to components and can improve the filling. Radii and fillets as small as 0.127mm can make improvement to components.

7. Surface Finish of Die Casting Parts

Die casting components’ surface finish depends on the finish of the tooling itself. Highly polished tooling surface will result in good surface casting components. The general die casting parts surface roughness are from 16 to 64 mircoinches. The die caster can easily produce matte finishes, as well as protruded logos and trademarks.

8. Parting Line and Ejector Pins for Die Casting

The parting line is the plane at which the two halves of the die meet. The designer must think through each part carefully, as much of the die cast success (or not) will depend on the construction of parting surfaces. The parting line should be kept as straight or flat as possible in general.

The ejector pins are the steel bars used to remove the casting component from the tooling. Good tooling maker will reduce the “visible” marks to minimum. Designer may advise on the appropriate locations of the ejector pins.

9. Identification Marks of Die Casting Parts

The designer should indicate where identification marks (logos, part numbers, etc.) are allowed. In general the die caster is tasked with putting the logo or part number. Typically they will also put on cavity number and date code to track the castings they made. It is easier to put these marks raised rather than recessed on the tooling.

10. Sliders in Die Casting Parts

The designer should try to avoid holes and undercuts that are parallel to the parting line if possible. The so called “slider” is the side core used to achieve these undercuts and holes. Slides are costly, and the designer and die caster should work together to simplify the design of castings and avoid using slides.

11. Function Combination of Die Casting Parts

The designer can combine component’s features in one casting and save on handling, storage and assembly costs.

12. Variations of Die Casting Parts

For similar parts (especially small ones produced at low volume), the designer might consider using

  • post machining/treatment, or
  • “multiple-inserts” (to change cavity)
    to achieve tooling cost savings through shared die cast toolings.
Die Casting Design Tips

13. Potential Part Cost Savings from Using Multiple-cavity Die Casting Tools

A die casting tool with multiple cavities can save part cost (since one die casting machine cycle can product multiple parts), but only if

  • the additional cavities do not result in having to use larger tonnage (and more-costly-tor-un) die casting machines (than a signle cavity tool would require), and
  • the additional complexity of the multiple cavity tool doe not result in signifcant reduction of yields.

One-stop services of  Die-casting & Custom Manufacturing in China

JINGXIN advantage:

  1. State-of-the-art Die Casting Facilities : 60,000 sq. ft. die casting floor space in China, 30 die casting machines for aluminum and zinc;
  2. Get the features you need. In-house CNC machining allows JINGXIN Die Casting to machine any element your casting requires. The latest technology means you can expect high-quality, repeatable machining of any type. We want to be your one-stop-shop for CNC machining and die cast services.
  3. Post Finish : We offer a series of post finishing services for die casting parts. The finish includes painting, electroplating, printing, powder coating, anodizing, sand blasting, E-coating, polishing, and passivation;
  4. We are ISO 9001 certified and our customers include some of the world’s toughest. Read More Quality control in House
  5. Customer Service Our highly skilled, English-speaking staff work directly with your design engineers every step of the way, from the design stage through product delivery. We own and manage the entire life cycle of a die casting manufacturing project.

What we do to make sure you would get the quality parts from JINGXIN Die Casting shop in China.

We declare here that We will be responsible for our precision Die Casting all the time.
1.100% inspection before shipping and inspection shipment report for each piece of precision Die Casting is available. (ISO quality control during the whole production).
2. We have served Volvo auto corp since 2016 as an approved precision CNC milling company in China. no complaint so far.
3. In case Any precision Die Casting that is outside tolerance and your special specification, we will remake and delivery as fast as we can;  100% free from our side.
4. For past years, JINGXIN Die Casting company has manufacturing thousands of pieces precision Die Casting components for our customers. 99.9% satisfaction feedback drives us to supply more quality precision machined parts to meet customer’s request.

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JINGXIN is the ideal supplier of One-stop Services for Die Casting & Custom Manufacturing Based in China!

Are you ready to start your next project? Tell the details or send CAD files for a competitive quote today.
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