The folded edge is a type of coin error caused by a marginal break along the edge of one of the blanking punches installed on the punching press. During the shearing of the planchet, the broken punch generates a metal tab on the edge, which is then flattened inward over the surface of the coin during the hemming process. As a result, the opposite edge of the coin also exhibits a discrepancy due to the different pressure to which the affected edge area is subjected at the moment of blanking.
