Expanded metal, a tried-and-true material, boasts remarkable versatility and finds utility across a spectrum of applications. Its adaptability extends to enclosure, safeguarding, manufacturing processes, construction projects, structural support, and even aesthetic embellishments. This material exhibits its prowess in various contexts and is frequently crafted from carbon steel, aluminum, and stainless steel. When presented in sheet form, its inherent attributes—strength, rigidity, and non-raveling qualities—interact harmoniously, fostering an open mesh structure. This mesh architecture is distinguished by its capacity to facilitate the unimpeded transmission of light, sound, heat, air, and liquids.
There is no doubt that expanded metal is a material that has been around for many years. It is an incredibly versatile material that can be used for anything from enclosures to protection to construction to support to decoration.
Carbon steel, aluminum, and stainless steel are the most commonly used materials for making the mesh. When it is constructed as sheets, the strong, rigid, non-raveling open mesh allows light, sound, heat, air, and liquids to pass through, but prevents unwanted objects (or people) from entering the space. Since each sheet of expanded metal grating is made from a single piece of robust steel, there are no joints or welds in the grating.
Expanded metal is available in two fundamental variations: Standard Expanded Metal (SXM) and Flattened Expanded Metal (FXM).
In SXM, the bonds and strands are at an angle to the original plane of the solid sheet after it has been die cut and expanded. The term “raised” often refers to SXM as a finished product after it has been die cut and expanded.
The FXM material has been cold rolled, leaving a smooth, flat surface. It is about 5 percent lighter than the SXM material.
Choosing a grating must be based on the design’s general characteristics, such as safety, open space, and ease of maintenance. After selecting the basic product, you will need to select the right style of grating for the job in order to satisfy the load-and-span requirements. Here are some tips for selecting the right style:
- Determine the clear span
- Determine the load condition and the amount of load
- Select the appropriate grating style
When placing an order for expanded metal, it’s essential to keep key considerations in mind. To start, the sheet size is denoted by SWD (Short Way of Diamond) followed by LWD (Long Way of Diamond), like this: SWD x LWD.
For catwalk applications, the LWD will typically run along the short edge of the expanded metal grating. For example, 30 pieces, 3.0# carbon steel expanded metal grating catwalks, 10 feet SWD by 3 feet LWD, providing greater support over the walkway’s span.
The sheet size and type of shearing should be stated, as well as the tolerance for dimensional dimensions, if special sheet sizes are required. Generally, expanded metal grating is sheared bond on the first bond over the specified dimension (both SWD and LWD). However, if required, it may be sheared randomly to a closer tolerance.
When ordering, specify the type of metal you would like. For example, carbon steel, stainless steel, aluminum, etc.
The following information should always be included when ordering expanded metal:
- Specify the number of pieces wanted
- Specify the nominal dimension of the diamond SWD (e.g., 3/4-inch)
- Specify the style of the sheet (e.g., #18; or if aluminum, 0.081)
- Specify whether standard or flattened
- Specify the type of material wanted (e.g., carbon steel, stainless steel, etc.)
- Specify the sheet size wanted (e.g., 4-foot SWD by 8-foot LWD)
Also, when it comes to expanded metal, it is important to brush up on some of the most important terminology.
As the name suggests, side shearing takes place when a piece of expanded metal is cut parallel to the long dimension of a diamond.
Normally, random side shearing is done parallel to the LWD dimension of the sheet, so you will end up with open diamonds on the surface of the sheet. The standard tolerance of the SWD dimension is +/- 1/16-inch when both sides of the sheet are sheared at the same time.
The bond side shear is a cut made along the length of the bond on the center line of the bond over a specified width. Since camber makes it difficult to bond side shear either regular or flattened metal, it is usually not practical to attempt bond side shear.
End Random Shearing results from shearing a piece of expanded metal to an exact length (LWD). This process normally leaves open diamonds at both ends, but results in close tolerance (+/- 1/16-inch) when both ends are sheared at the same time.
A diamond is end sheared by cutting a piece of expanded metal parallel to the diamond’s short way by means of a knife.
When end bond shearing is performed, a piece of expanded metal is sheared to a specified length (LWD). A +/- 1/16-inch tolerance is applied to both ends. One end is cut on the bond parallel to SWD, while the other end usually has an open diamond pattern. (NOTE: End bond shearing is performed over the specified length with a tolerance of +/- 1/2 diamond when both ends are sheared.)
Squareness refers to shearing all four edges of a sheet, with a maximum tolerance of 1/16-inch per foot.
In addition, bond shearing produces closed diamonds that are easier to handle and safer to handle, but it often results in higher costs and requires greater dimensional tolerances. In most cases, random shearing is less expensive, except where scrap (“drop off”) is excessive, is more difficult to handle, and poses a greater safety risk due to the sharp edges remaining on the diamond.
So as you can see, the world of expanded metal is far from flat. A licensed architect and/or contractor is always the best person to consult for your specific job. It is multi-dimensional, with many factors to consider when choosing the right type and cut.
If you would like to learn more, please visit //www.huijinmaterials.com/
If you would like to learn more, please visit //www.huijinmaterials.com/
