At the point the raw material yields, it fractures; the slug can fall with minor resistance, and tonnage drops rapidly.
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Close-up of a burr Holes with less than the thickness dimensions There are situations in which it is necessary to make holes with no dimension less than the thickness of the steel.
Punching is factor chip removal type process and should not be used to cut large amounts of material. In this case the and is added to the penetration in the die making it larger than the desired hole size.