Producing the best die cast parts starts with a solid design. There are many factors involved in the creation of a die for casting and once the die is in place and the metal starts pouring, there are few other changes you can make although they may cost money to modify the tooling if required. That’s why it’s important to follow good die casting design guidelines from the start.
Keep in mind that the goal in die casting design is to create castings that will maximize the functionality of the product while being able to produce products quickly and efficiently with minimal chance of defects. To service this goal, some of the design tips to keep in mind include:
Wall Thickness Uniformity
One goal of die casting should be to make a design that creates uniform wall thickness all around the casting. You may not be able to create 100 percent uniformity, but you should be able to significantly minimize wall thickness variations in your die casting. Different wall thicknesses can result in different rates of cooling along the casting walls.
Different cooling rates can create numerous problems for a casting, including variations in the dimensions of your part. Uniform metal thickness is also better for metal flow and complete casting filling, meaning a higher-quality product.
Large Fillets and Corners
Try to make the inside and outside corner radii of your casting as large as possible. This will provide a number of benefits, including decreasing degradation of die steel in the corners, improved metal flow, a stronger component and easier finish application.
Ribs and Bosses
When possible, include ribs and bosses in the casting design. You can use these to eliminate sharp corners and increase the strength of the finished part.
If you need a lightweight part, you don’t have to cast a part that is 100 percent solid. With the right approach, designing a casting with strategic air pockets (we call these “metal savers”) to thin the cross-section can make your part much lighter without sacrificing structural integrity. You can use ribs to strengthen the component after thinning if necessary.
When we use the term “draft” with respect to die casting, we refer to tapered walls for walls that run in the direction of the die open/close movement. If you try to design your cast without them, you will not be able to remove the casting from the die. Make sure you design your die casting with taper on the inside walls greater than taper on the outside walls, because when the alloy solidifies, it will shrink and fit more tightly on the inside casting. Greater interior draft means easier casting removal.
Same Side Die Dimensions
Another very useful design idea is to make sure your critical dimensions are all on the same die side. This will mean you will require fewer operations to meet tolerances, which means a more cost-effective die cast.
If you have undercuts in the part design, your regular die cast mold will not work. You will need to add a slide (this is a moving member of the mold perpendicular to the direction of the die draw), which increases the time and cost of the casting. If you can avoid undercuts, you should.
Learn More About Quality Die Casting Design
For more than 70 years, Premier Engineered Products has provided high-quality metal forming services to a wide range of industries. Our aluminum casting expertise is unmatched and we can design just the die casting you need for high-quality parts for all your applications every time.
To find out more about the benefits of Premier Engineered Products services, contact us today.