Expanded Metal vs. Perforated Metal: Which One to Choose?

When choosing a metal for any application, you will always be torn between two main types of metals. These are expanded metal and perforated metal. Each metal has its own unique characteristics. The differences between these metals may be due to material, chemical composition, properties, and structure. In this article, we will examine the differences between expanded metal and perforated metal.

History of Perforated Metal

The industry of perforated metal sheets originated in the 19th century in the coal mining industry. Perforated metal sheets were used to separate the coal and the holes were punched manually.

Decorative Perforated Metal     

Manual perforation was eventually replaced by more efficient methods. These included "cold perforation," in which rollers filled with pins were run through the metal sheet to punch the holes, and "hot perforation" - a similar technique, but using heated pins to create a veneer around the holes.

There are also punch and die processes, in which sheets with protruding needles are pressed against the metal sheet as they roll through the punch, and laser perforation, in which the holes are burned into the metal.

History of Expanded metal

The expanded metal manufacturing process was invented by John French Golding – and the first British patent was issued to him in 1884. John was the founder of The Expanded Metal Company and with Mathew Gray, Christopher Furness, Robert Irving Jr., and W.B Close brought the manufacture of expanded metal to Hartlepool.

Decorative Perforated Metal

How Perforated Metal is Manufactured?

As with expanded metal, the perforated metal starts with a steel sheet. However, instead of slicing and stretching the sheet, the technician feeds the substrate into a specialized machine that punches holes in a predefined pattern (usually straight or interlaced hole lines). The machine usually leaves a thin piece of metal unperforated around the perimeter to avoid affecting the stability of the material.

The perforating process inevitably generates waste. While it is possible to recycle the excess metal, doing so may increase the overall project cost. Manufacturing sheets with larger holes creates more material waste - resulting in higher production costs - so customers with such requirements should consider whether the extended metal is a better fit for their budget.

How Expanded Metal is Manufactured?

The key to the strength of expanded metal lies in its fabrication process. The first step is to punch holes in the sheet with a series of regular slits. Adding these openings and stretching the sheet creates a unique repeating diamond pattern that distinguishes expanded metal from other material options. Some metal strands may protrude slightly after the stretching process, but they can be flattened later if desired or needed.

Decorative Expanded Metal Panel

Applications of Perforated Metal

Perforated metal appears to be the industry standard for construction applications such as building facades, fences, and partitions. Because perforated metal is stamped and cut, molds can be designed to cut patterned shapes into metal panels for a variety of purposes, both decorative and functional. The shape of the metal perforations can determine how useful the material is in blocking microwaves, sound waves, or light; perforated metal is used in all of these industries. Next time you heat up some leftovers, take a look at your microwave door. See that filter in the glass? That's a perforated piece of metal that blocks microwaves from passing through the door.

Sound insulation and acoustic enhancement is another important application for perforated metal, which can muffle, block or soften sound in structures that are too large to be soundproofed with foam acoustic panels. Theater lights and laboratory lights are often filtered and diffused with perforated metal, and large office buildings or corporate structures can benefit from the decorative and sound deadening properties of interior perforated wall panels.

In addition to architectural uses, perforated metals can be useful in many filtration applications when made into perforated tubes. These are often used in in-line processes to filter fish eyes or other agglomerates during pharmaceutical, chemical, or food processing.

    Decorative Perforated Metal 

Applications of Expanded Metal

When choosing to use expanded metal for an application, some of the key considerations include thickness and strand dimension, both of which depend on the structure’s requirements. It is available in a wide range of materials, mesh sizes (including near-transparent thickness), and pattern designs to suit different use cases.

Airbags

Automotive racks

Ceiling panels

Chimney caps

Ceiling panels

Lockers

Machine guards

Screening

Applications of Expanded Metal 

Expanded metal sheets, while capable of being used in many of these applications (with the exception of soundproofing), excel in a completely different area. Stair treads, walkways, catwalks, and floor grating are common in industrial facilities, construction sites, and even many commercial buildings, and they are all made of industrial expanded metal.

Expanded and Perforated Metal Solutions from BZ WIRE MESH

At BZ WIRE MESH, we recognize the value of expanded and perforated metals. As a result, we offer our customers a wide range of perforated metal materials and expanded metal products. No matter which material you need, our dedicated sales and engineering teams will ensure you get the right product for your application and requirements.

For more information about our products or to help select a product for your next project, contact us today or request a quote.