All About Sheet Metal – Materials, Standard Sizes & Forming Processes

Sheet metal is the basis of all engineering today. We can see it everywhere – from cars and machinery to house facades and furniture.

To utilise sheet metal to its full extent, engineers should first know a thing or two about it. This includes standard measurements, materials, differences in manufacturing and possible forming methods.

What Is Sheet Metal?

Sheet metal is one of the shapes and forms metal can be bought in. Sheet metal is any metal that has a thickness in between 0.5…6 millimetres.

There are other measurement units used to categorise metals by thickness, though.

Millimetres, Mils & Gauge

Foils, sheets and plates are pretty much the same, with the only difference being in thickness. Thickness is measured in 3 ways – millimetres, mils and gauges. While millimetre is a pretty straightforward unit, mils and gauges are only common in engineering and manufacturing.

One mil equals to a thousandth of an inch. As the British often use “mils” as a plural for millimetres, it can be a little confusing but the difference is important.

Gauge is another unit for measuring sheet metal thickness. Although official standards discourage the use of gauges, they are not all that rare. Gauge represents the thickness of a metal in relation to its weight per square foot. A higher gauge number means a smaller thickness. sand casting company

As it is related to the weight of a metal, the actual thickness (mm) for the same gauge, is different for various metals (e.g. 12 mm steel vs 12 mm aluminium).

Foil, Sheet and Plate

Having gone over the primary measurement systems, we can now look at the categorisation of foils, sheets and plates. For our purpose, we are going to stick with millimetres as the unit of measurement.

Metal foil is especially common with aluminium, often referred to as tinfoil. The thickness of foil is usually up to 0.2 mm. 

Sheet metal is the next in line. The thickness of sheet metal starts from 0.5 mm and goes up to 6 mm. Anything above that is a metal plate.

The thin sheet metal is easy to form, while still providing great strength. At a relatively cheap price, it makes a great fit for most engineering purposes. That is why we see it everywhere around us.

At the end of the article, we will be discussing different forming methods used with sheet metal.

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