Perforated product producers are able to create a wide array of hole shapes and patterns in material sheets through the use of standard and custom punches, computerized punching pattern programs and special fabrication techniques.
Below, we will discuss the types of hole shapes and patterns available, as well as the applications and costs associated with each.
The types of hole shapes available in perforated products is limited only by the technological ability to machine the cutting dies into a specific configuration that can not only create the shape, but withstand the stresses of the punching process. The most commonly used and most affordable hole shapes are:
- Round Holes. A round hole is the easiest and most economical shape to incorporate into a perforated sheet, as the relative simplicity of machining a round piece results in low manufacturing costs. Round hole patterns are used in a variety of applications, including air-conditioning and heating systems, decorative finishes for architectural installations, and more.
- Square Holes. Square holes are able to provide a significant amount of open area and a clear view through finished sheets, while also providing a strong barrier that can be used to resist impact loads, prevent contact with equipment or prevent entry of trespassers into protected areas. Increased wear on equipment occurs during the square hole perforation process due to the tendency of the punches to suffer increased stresses near the corners of the square shape. For this reason, the creation of square hole patterns increases the cost of production over that of round holes.
- Slot Holes. Slot holes consist of long rectangles with a half-circle or square ends. These are versatile shapes in the manufacturing industry, as they are applicable to screening and sorting of materials, particularly long thin items such as seeds and grains. Slots can be installed parallel to either the width or the length of the sheet depending on user preference and needs of the application.
The standard pattern types used for perforating metal are straight line and staggered, which fit the majority of perforated metal uses. Non-standard patterns are also available for custom applications. The various types of perforated metal patterns include:
- Straight Line. Straight-line perforated metal layouts consist of repeating rows that contain an identical number of holes in each row and follow the same alignment down the sheet as it is pulled through the punch. Straight patterns are designed by specifying both the distance between holes and the distance between successive rows of holes.
- Staggered Layouts. Staggered layouts consist of repeated patterns that have offset alignments from the adjacent rows as the sheets are pulled through the punch. Staggered layouts are specified based on the angle between centers of successive lines of holes. For instance, one of the most common patterns is a 60° staggered pattern, which means that after one row of holes is punched, the die moves over and punches the next row in such a manner that the line drawn from the center of a shape on the previous line to the center of an adjacent shape on the new line forms a 60° angle from the previous row.
- Non-Standard. Non-standard patterns, such as circle, spiral and star patterns increase the cost of the perforation process, primarily as a result of the increased production time required to create these layouts. As with the hole shapes themselves, utilization of patterns that are relatively symmetrical can help to reduce the overall cost of the perforated sheets.
Find Out More about Hole Shapes and Patterns
Hole shapes and patterns have a sizeable impact on the cost and performance of your perforated product. Knowing these specifications helps eliminate roadblocks when bringing your project to a manufacturer. To learn more about the qualities of perforated products, download our free eBook: Proper Selection for Perforated Products.