The relationship of the larger die hole size to the punch size is die clearance and is stated as a percentage of the thickness of the material being punched. The range of clearances varies from 10 percent for thin materials to 20 percent for thicker materials. For 3/4″ material the total die clearance is .150″. Clearance should always be specified when there is any reason for doubt.
Die Clearance has the following effects: