Round Holes are the most popular shape and give you the widest selection of diameters, gauges, materials and sheet size options. Holes are in staggered row (most popular) or straight row patterns.
Hole center is the distance fron the center of one hole to the center of the nearest hole is the next adjoining row. Hole center is one of two measures of perforation spacing. The other is open area. Because of the hole center and open area measure essentially the same property (perforation spacing),you need specify only one or the other.
Round holes ranging from under .020˝ to over 6˝ account for 80% of the production of the perforating industry. This shape is the most versatile in its application and provides a wide range of open areas as well as a handsome appearance. Round holes are produced with greater efficiency and less expense than any other hole shape. The dies and punches that make round holes are the most cost efficient to build and maintain.
The degree Staggered Round Hole Pattern
The degree staggered formation is the most popular hole arrangement because of its inherent strength and the wide range of open areas it provides. The diagram below illustrates the essential die design and perforating practices for producing 1/4˝ round holes on 3/8˝ centers in a degree staggered formation.
The basic perforating die layout includes two rows of punches, arranged as the illustration shows, in an open staggered pattern. The actual punches in the die are indicated by the solid black holes. The feed of the press is from right to left.