Applications of tin and tin alloys: where tin is used

Tin is a soft silvery-white metal with the chemical symbol Sn. It has been known since ancient times, rolls easily into thin sheet, has a relatively low melting point of about 232 °C and oxidizes slowly in air. Because of these properties, tin is used both as a metal in its own right and as a component of solders, coatings and alloys.

Tin and its properties

Pure tin is ductile, melts easily and forms a protective oxide film. The metal is resistant to water and many mild environments, so it is useful where a thin protective layer or a low-melting metallic component is needed.

At the same time, pure tin is soft and is not suitable for most loaded parts. That is why industry more often uses tin alloys or tin coatings: they provide the required strength, wear resistance, corrosion resistance or processability.

Where tin is used

• Solders. One of the main uses of tin is in solders for electronics, electrical work, plumbing and assembly operations. Tin lowers the melting point of solder and helps create reliable joints.
• Tinplate and tinning. A thin layer of tin is applied to a steel base to protect it from corrosion. This produces tinplate for cans, lids and other packaging.
• Chemical compounds. Tin compounds are used in PVC stabilizers, catalysts, some coatings and special materials.
• Protective coatings. Tinning is used for parts, contacts, wire, cookware and components that need protection from moisture and oxidation.
• Batteries and electrical engineering. Small additions of tin are used in some alloys for battery grids, contacts and current-carrying parts.

Applications of tin alloys

Tin is part of many alloys. The best-known examples are bronzes, babbitts, solders and some decorative alloys. In each case, tin has a specific function: it improves casting behavior, lowers melting temperature, increases corrosion resistance or affects friction.

Tin bronzes are used for bushings, plain bearings, fittings, art castings and parts that need wear resistance and stable operation in friction units. More about these materials is covered in the article on bronze applications.

Babbitts are antifriction alloys based on tin or lead with additions of antimony, copper and other elements. They are used in bearing units where good conformability and operation with a thin oil film are important.

What to consider when choosing tin

For practical use, it is important to consider not only the presence of tin but also the alloy composition, contact with water, temperature, load and safety requirements. Solder for electronics, coating for packaging and babbitt for a bearing are completely different materials, even though all of them may contain tin.

Related article: tin specific weight and density.