Raw Materials

Perforated materials, high tolerance, precision manufacture

Mild Steel

Mild steel is the most corrosive prone and therefore the least expensive of the three most commonly perforated metals.

The mild steel is manufactured in either sheet or coil form by roller, flattening it to the desired thickness either initially, whilst the steel is still hot, or after it has cooled. These Mild Steel types are referred to as either Hot Rolled or Cold Rolled, and differences in the processes result in products that differ in terms of cost, quality and mechanical properties.

Hot Rolled Mild Steel is typically less expensive and produced in thicker gauges of 1.5mm upwards, whereas Cold Rolled provides tighter tolerances, better surface finishes, and while it can be produced in practically any gauge, it is most readily available in thinner gauges from 1.5mm down to 0.4mm.

Due to mild steel being susceptible to corrosion, it is used in either unexposed applications or with a protective coating. Coatings such as paint and powder are applied after perforating mild steel and completely protect the material. On the other hand, zinc and aluminised based coated metals (i.e. Aluminised Pre-Galvanised, Galvannealed, etc.) that are produced and supplied from the mill, may not completely protect the material where the mild steel substrate is later exposed during the metal perforating process.

Stainless Steel

In many situations, galvanic protection from painting a mild steel surface is impractical. This is where the special oxide film formed on Chromium alloyed Stainless Steels becomes useful, greatly increasing the applications for stainless steel perforated sheet metal.

Many types of stainless steels have been developed to resist different corrosion environments and working conditions; for example, ensuring that workings are safe, things last longer and our food is hygienic. Stainless steel is even used to clean up the exhaust gases from cars and power stations.

Stainless steel is also recyclable: when scrapped, it can be re-melted and reused.

Properties in machining, forming, welding etc.


Aluminium is corrosion resistant. It is, however, much lighter and softer than stainless steel and mild steel. To prevent the dull appearance that results from the oxidation of the outer layer, Aluminium perforated sheet can be either clear or colour anodised after perforating. Unlike paint or powder coating, anodised film is built from the aluminium itself and takes on a translucent appearance. Common uses for perforated aluminium are building projects, baking trays and other domestic appliance applications.


Perforated plastics have many miscellaneous uses, most commonly as a perforated material for filtration, but perforated plastic has been used in speaker applications. Bion advancement in tooling means that we can perforate a clean hole in plastics without any “feathering”. Our sheet levelling facilities enable us to supply a superior flat perforated plastic product.

If you require information on the other types of material we can perforate, please call +44 (0) 118 959 2700 or email websales@bion.co.uk