Progressive Stamping Mold: Spacing Limitation

In January, we have talked about a new progressive stamping project for making a straight flat actuator of micro switch. In general, the reason why we built a progressive punching mold for production is based on annual demand of the project. You are also welcome to visit the previous case study to check out what a progressive stamping mold is.

Spacing limitation of stamping mold

Regarding micro switch, there are lots of different type of actuator. Depending on application, straight flat, out hole, rollover, with blade and roller, etc. The micro switch which our customer required was the simple one with medium lever flat blade. At present, our customer had approved the FA samples which were perfectly machined as per CAD drawings. However, they were also asking if we can increase the distances from both hole center and radius edge to flat surface. Distance from radius edge to flat surface changed from 0.145″ to be 0.166″. Distance from the hole center to flat surface changed from 0.082″ to be 0.103″. Check out the modification in below drawing.

To increase the distances from both hole center and radius edge to flat surface, the stamping mold should also be modified accordingly.
Modification(red marked dimensions) of the micro switch stamping mold


During the punchinging process, the progressive tooling will cut, pierce and bend each of micro switch step by step. No matter how the designer or engineer modified the parts,  the features or dimensions should be exactly relative to punching die. As per customer’s requirement, the flat pattern of micro switch is getting wider. In short, the spacing between each stamping stage is also getting smaller. Moreover, the smaller the spacing is, the smaller the punching die is.

Optimized spacing between each stamping stage

However, smaller punching die does have negative effect on the life time of punching die. In our original design, the spacing was 2.0 mm for saving raw material and also good life time of punching die. If changing the parts width from .145″ to .166″, the spacing between each stamping stage will be down to less than 1.0 mm. No doubt that the punching die will definitely damage very soon. Thus, our USA client had placed another mold order for new design with optimized spacing.

Optimized spacing between each stamping stage
Progressive stamping mold with optimized spacing

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