How Is Expanded Metal Made?

The process for creating expanded metal was first developed and patented in the 1880s in Hartlepool, UK. Understanding how expanded metal is made is fascinating because, despite technological advancements, the modern process for expanding metal remains similar to the original technique.

The question of how expanded metal is made often surprises people with its simplicity and efficiency. The basic principles behind how expanded metal is made involve precision cutting and stretching of solid metal sheets, creating a product that’s both lighter and stronger than its original form. So, how is expanded metal made?

What Is Expanded Metal?

Expanded metal is a plate or sheet that has been cut and stretched into a mesh. Stretching the metal results in a mesh with diamond-shaped spaces – although many other patterns can be created. Many types of metal can be expanded, including stainless steel, hot-rolled steel, cold-rolled steel, aluminum, and more.

The mesh pattern can be staggered (providing the most open area) or straight, with all rows and columns aligned. The proportion of open area determines the amount of space for the passage of air, water, and light and will vary according to the intended application of the expanded metal.

When examining how it’s made, expanded metal demonstrates remarkable versatility in design options. The expanded manufacturing process allows for customization of thickness, pattern size, and material type, making it suitable for countless industrial, architectural, and functional applications.

Benefits of Expanded Metal

There are several benefits to using expanded metal:

• Cost-Effective: A small quantity of metal can be stretched into a large piece.
• Efficient Process: There is very little waste when manufacturing and processing expanded metal mesh.
• Good Conductor: Because expanded metal is one piece, it can be an excellent conductor of electricity, magnetic flux, and heat.
• Protective Reinforcement: Expanded metal meshes can be combined with glass, concrete, and other materials for added strength.
• High Strength: Expanded metals support weight and withstand stress better than woven metals or jointed welds.
• Low Weight: Expanded metals are lighter than traditional metal sheets.
• Allows Circulation: Expanded metal allows air and light to move freely.
• Acoustic Properties: Specially developed meshes can enhance acoustics and provide soundproofing.

How Is Expanded Metal Made?

Here’s a detailed breakdown of how expanded metal is made:

1. Expanded metal begins with solid metal sheets or coils that will be transformed into mesh.
2. The expanded metal manufacturing process utilizes a specialized expanding machine fitted with a precision knife that determines the pattern for the mesh.
3. Sheets or coils of metal are carefully fed into the expanding machine.
4. As the metal moves through the machine, expanded metal making involves a pressured slitting and stretching process that happens at the same time.
5. The slits created by the knife allow the metal to be stretched, producing uniform holes throughout the material.
6. To ensure a consistent pattern, the expanding machine is either programmed or operated manually as the metal continues to feed through.
7. Once the expansion is complete, the finished expanded metal is either wound into coils or cut into sheets, depending on customer requirements.

Depending on the intended application, different metal thicknesses and mesh patterns can be used. L.W.D. (Long Way Diamond) and S.W.D. (Short Way Diamond) are commonly used to indicate the desired length and width of the diamond-shaped holes in the mesh.

The efficiency of how expanded metal is made is remarkable. There is virtually no material waste as the metal is slit and stretched rather than cut out, making this process both economical and environmentally friendly.

Types of Expanded Metal

The most common types of expanded metal are:

Standard Expanded Metal

Standard expanded metal is extremely versatile and economical. It comes in a variety of gauge and opening sizes. It’s often used to provide a rigid, raised, slip-resistant surface. In standard expanded metal the strands and bonds are set at a uniform angle. This provides extra strength and rigidity whilst allowing maximum air circulation.

Flattened Expanded Metal

Flattened expanded metal is produced by cold rolling expanded metal to flatten it. It is chosen when a smooth surface is required. The flattening process generally increases the sheet’s length by 5%.

Hexagonal Expanded Metal

Hexagonal expanded metal has hexagonal openings rather than the usual diamond-shaped ones. The hexagonal shape gives the metal extra strength while allowing the passage of air, light, heat, sound, and liquid. Hexagonal openings are preferred over diamond openings when the metal is heavily expanded.

Architectural Expanded Metal

Architectural expanded metal features the diamond pattern with added architectural features. The result is a design that combines good aesthetics, increased security and privacy, and improved ventilation. It’s suitable for functional and decorative purposes, or a combination of the two.

Micro Expanded Metal

Micro expanded metal features small openings in light-gauge metal. The openings can be standard, flattened, hexagonal, and square. This type of expanded metal is often used in filters.

How Expanded Metal Is Made

The process of how expanded metal is made has remained relatively unchanged since its inception in the 1880s, proving the enduring value of this innovative manufacturing technique. The simultaneous cutting and stretching involved in expanded metal and how it’s made ensures material efficiency while creating a product that’s stronger per kilogram than the original sheet.

The beauty of how expanded metal is made lies in its simplicity and effectiveness. Whether you need standard diamond patterns or specialized designs, the expanding process can accommodate a wide range of specifications. Next time you encounter expanded metal in a security fence, architectural facade, or industrial filter, you’ll have a deeper appreciation for the manufacturing process that created it, which combines strength, versatility, and material efficiency.