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Archive: Mar 2015

  1. Choosing the Right Hole Shape & Pattern for Your Perforated Product

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    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.

    Shapes

    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.

    Patterns

    Perforated Hole Shapes & PatternsThe 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.
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  2. 3 Traits of Perforated Sheets to Identify before Ordering from Your Manufacturer

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    Perforated SheetsPerforation of material is accomplished by using mechanical means to penetrate, or “punch”, through material surface, leaving behind a hole of particular size and shape. In practice, perforated material typically consists of flat sheets that are modified by creating recurring patterns of punched shapes.

    Implementation of perforated products into any project requires knowledge of the cost implications associated with specific metal configurations. It is important to understand the various characteristics of a sheet and the options available when specifying the product to be produced.

    Before ordering custom perforated sheets, the buyer must typically specify these three traits:

    1. Material Type and Thickness

    There are many types of materials suitable for perforating, with what is most applicable for the specific projects dependent upon the material cost and properties. Commonly used materials for perforated metal are:

    • Hot-rolled and cold-rolled carbon steel
    • Galvanized Steel, typically pre-galvanized (galvanized prior to punching)
    • Stainless steel (Type 304 and 316, both standard and low carbon varieties)
    • Aluminum
    • Brass
    • Copper

    Material thickness is also important to consider, especially since the cost of fabricated pieces is typically derived from the “per pound” price of the material, and perforated pieces are no exception. The thinner the perforated sheets, the less material used to create the finished piece, and therefore the lower the price per piece.

    In addition to simply saving on material cost, it is easier for shops to punch and work thin(ner) sheets than it is to machine thicker pieces, which creates an associated savings in production costs as well. It is important to remember, however, that decreasing the cross-section of the sheets by choosing a lesser thickness will create a decrease in the structural capacity of the sheet.

    Utilization of higher-strength pieces can, in some cases, result in an overall reduction in the number of pieces that are required. The designer must balance material thickness versus structural requirements to ultimately decide on the best way to achieve a cost-efficient project.

    2. Hole Shape and Size

    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.

    • 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. 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.
    • Hole size is determined by drawing a circle around the hole shape with a radius that extends from the center of the shape to its extreme outside edge. Typically the hole size is greater than or equal to the thickness of the material being punched, in most cases much greater. For high-strength material such as stainless steel, the hole size must generally be at least 2 to 3 times the thickness of the metal sheet in order to provide a clean cut, easier manufacturing and reasonable cost.

    3. Margins

    The end margin width on perforated sheets is normally zero, which means that there is no distance between the perforated patterns and the end of the sheet. This is known as an “unfinished pattern” and occurs when the punching continues to the ends of the sheet and the holes do not complete their last cut cleanly inside the sheet borders.

    Stock sheets are most commonly available in an unfinished pattern configuration. It is also the least expensive way to fabricate a piece from scratch. If desired, a minimum margin width can be created on the ends, but require adjustments to the perforation process, resulting in more expensive sheets.

    Learn More about Criteria Involved in Manufacturing Perforated Sheets

    Knowing the exact specifications of your perforated product can help accelerate the project’s completion — and lets you know what to expect in terms of cost and timeline. To learn more about the factors that go into selecting your product, download our new eBook, Proper Selection for Perforated Products.

    Click to Download