What is tin used for?

Tin: properties of an indispensable metal

If you bend the relatively soft, high-purity tin, you will hear a typical noise - the so-called tin scream. But even small amounts of contamination, for example with lead, mean that the pewter screaming no longer occurs when it is bent.

In the air, tin is coated with a thin oxide layer, similar to aluminum, and is very resistant.

Metallic tin is non-toxic, even in large quantities, and therefore completely harmless. However, there are organic tin compounds that are highly toxic.

These connections are used to paint ship hulls, for example. The paints contain trialkyl tin compounds or triphenyl tin because these kill microorganisms and mussels that have settled on the ship's hull.

Pure tinplate has been used in organ building for centuries. It is used in the visible area of ​​the organ because it retains its silver color for decades.

Most organ pipes, however, have some lead mixed in with them. This alloy, known as so-called organ metal, has vibration-damping properties compared to pure tin.

Risk of tin plague

Because the tin changes its crystal structure at lower temperatures, it is harmful to organ pipes. The conversion starts at 13 to 16 degrees, the ideal conversion temperature is reached at -48 degrees Celsius.

In specialist circles one speaks of the so-called tin plague.

The alpha tin that forms at lower temperatures takes up a larger volume than the beta tin. As a result, the material loses its stability and tin powder is produced.

In earlier centuries, many household items such as dishes, tubes and cans were made entirely of pewter.

For example, it is reported from Napoleon's Russian campaign that the buttons on the soldiers' uniforms had crumbled in the face of the low temperatures.

Today the comparatively expensive tin is increasingly being replaced by cheaper alloys or alternatives.

Aluminum in particular displaced tin in the 20th century. The main reason for this development is the lower price of aluminum.

Today the tin is mainly used as tinplate, a tin-plated iron sheet. It is used for tins and baking tins.

Tin that has been rolled out into a thin foil is called tinfoil. Just a few weeks ago, this film, cut into fine strips, decorated countless trees in German living rooms as tinsel.

Tin: an important alloy metal

The uses of tin as an alloy metal are very diverse.

In addition to bronze as the best-known alloy in which tin appears together with copper, we mainly come across so-called Nordic gold in everyday use.

This alloy, which gives the euro coins their gold-colored character, contains, among other things, 1% tin.

Tin is particularly popular when it comes to producing metal alloys with a low melting point.

Soft solder, the so-called soldering tin, used to contain a mixture of 63% tin and 37% lead. Its melting point is around 183 degrees Celsius.

Since lead-containing tin solder can no longer be used in electronic devices since July 2006, lead-free alloys of tin, copper and silver are used today.

As a result, the melting temperature has increased slightly to 220 degrees Celsius. However, there is little confidence in the stability of these alloys.

For this reason, lead-free tin solder may often not be used in consideration of the tin plague.

This is the case, for example, in the manufacture of electronic assemblies that are intended for measuring devices, the aerospace industry, medical and security technology as well as police and military applications.

The worldwide annual consumption of around 300,000 tons is distributed roughly evenly over the applications described above. 35% of the tin is used for solder, around 30% for tinplate and another 30% for paints and pigments.

Not only does China have the highest tin production, it is also currently the largest consumer. Germany is already the fourth largest consumer, behind the USA and Japan.

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