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Showing posts from December, 2015

The Importance of Proper Cutting Clearances

By: Peter Ulintz, PMA technical director
An important requirement of any die operation is the proper alignment between all the working components. In stamping operations, accurate alignment is necessary to maintain proper clearances between punch and die steels. Cutting, punching and trimming operations require cutting clearances that are held within close limits. Because many stamping features are not symmetrical or totally round, cutting clearance usually is measured at one side of the cutting profile and specified as a “per-side” clearance. The amount of clearance applied and the sharpness of the cutting steels have a direct effect on the quality of the sheared edges. When the cutting clearances are small, press and die alignment becomes critical. If this alignment is not maintained properly, the punch and die details may contact each other and the cutting edges may be damaged. Clearances that are too tight will produce an edge defect known as secondary shear - sometimes referred to…