One of CWM’s Sales Engineers coined the phrase, ‘Start with the finish in mind.’ This is because the specific design features of a die cast part, in almost every case, has a direct impact on achieving the required surface finish specifications. For this reason, all die casting finishing requirements should be discussed with the die caster early in the design phase.
Die castings and subsequent surface finishes have a symbiotic relationship. That is, the results of each process “work together,” and each benefit from the relationship. For example, aluminum die castings that call for a cosmetic surface will require attention to the location of the casting’s parting line, gate, overflows and vents. If these design features interfere with or blemish any of the part’s designated cosmetic surfaces, undesired results will occur.
The importance of reviewing the finish with the die caster early in the project is also exemplified by the tool design. Cosmetic surface requirements for the custom die casting may require special finishing of the cavities of the die. In addition, the cover die half will generally be used to produce a specified cosmetic surface. This permits the ejector die half to contain the required ejector pins— which assist in ejecting the part cleanly from the die.
It is essential that the die caster understands how parts mate with other components in the final product assembly. The die caster will analyze the design to assure a quality finish, and equally important, to make sure that tolerance specifications will be met. If this step is omitted, it could lead to additional finishing processes that increase piece price costs.
Cost is certainly another driver to have an early discussion with the potential die cast supplier. As discussed earlier, the geometry of the design’s features have a direct impact on the final surface finish. An early review with the die caster can result in minor modifications (i.e., critical surfaces, edges, and mounting features) that reduce the need for surface preparation before the final coating. The end result is increased efficiency which has a direct impact on lowering the final production cost.
Unlike many die casters that only produce raw castings, CWM is a full-service, die cast-to-finish supplier. Over 90% of our castings include additional post-cast finishing operations prior to shipment to our customers. With that high volume of post-finishing experience, coupled with over 75 years of performance, our die cast finishing expertise is unsurpassed. Further, when it comes to recommending the right alloy with the optimal finishing process, CWM is in a unique position to provide unbiased information since we work with the most widely used metals: aluminum, magnesium and zinc. If you would like to tap in to that experience by reviewing your project with a CWM Sales Engineer, please call us at 630-595-4424.