Casting Study: Foot Switch – Control International

Over time, the costs associated with machining the cast-iron switch cover eroded manufacturing margins. The decision was then made to zinc die cast the cover. Zinc had the density and weight Control International specified, and it provided better fit, quality, and surface finish than cast iron. Tolerances are held to 0.005 in. with better definition and detail. In fact, they now emboss their company name crisply in the cover, something that could not be done with cast iron. Die casting also eliminated the swell, shift, and inconsistencies associated with the iron part.

The primary cost savings came from eliminating some secondary machining operations. Where they had to drill three holes in the cast iron cover, they only need two hinge holes in the zinc cover. Machining is also much faster because of the excellent machining characteristics of zinc alloys. Because the zinc die castings store without rusting, the company often saves an extra cleaning operation before the switches are painted.