“Tin Plating: Not Just For Cans Anymore”

 



Text Box: ~ Basic Properties of Tin ~
•	Durable, can be severely worked and deformed. 
•	Excellent corrosion protection. 
•	Does not tarnish easily, a good choice as a decorative finish.
Moderate Cost
An important commodity in international trade, TIN occurs naturally as the mineral cassiterite, an oxide of tin with the chemical formula SnO2.

Once refined, tin is a silver-white, soft, ductile, and malleable metal.  Available worldwide, cassiterite is found either in rocks, irregular veins or lodes, or in alluvial deposits, which are found in riverbeds, valleys, & the ocean floor.

Primary Uses:

·        Electronics:  Tin is only a moderate conductor of electricity, but since the thickness of the tin plating is usually 0.0005" or less, the distance traveled by the current is very short, and therefore, not high in electrical resistance.  Tin is the best choice of the commonly plated metals used in electronics applications for marine and other high humidity atmospheres.  In electronics, tin is commonly used for: 

·        Soldering, as tin is compatible with solders used for the joining of electronic components.

Note: Tin used for electronic soldering has a shelf life, as its solderability degrades over time, depending on the storage conditions and plating itself. 

 

 

 

·        Bolted Grounding Connections: Electronics normally begin to operate poorly, or fail due to the corrosion of the electrical connections.  Tin-plating on brass and copper conductors solves this problem. 

·        Airtight Bonding: Tin is used to secure bonds in bolted connections, as even when the tin does corrode (oxidize); the tin oxide layer is a very ductile, thin layer.  When two tin plated surfaces are mated under pressure the surface layer will crack and displace, allowing the pure tin molecules to cold weld, forming an airtight bond that inhibits further oxidation in the connection. 

Food Storage & Cooking: Tin plated sheet steel is the primary material for food canning, and shares the beverage can market with aluminum.  Tin is also commonly used in bake ware and food storage containers, and offers a safe, non-toxic coating for food handling and preparation equipment, being resistant to most food acids, ammonia, and neutral solutions.

Plumbing:  Pipe Solders containing lead are being replaced by safe tin-silver (usually 96.5 percent tin/3.5 percent silver) or tin-copper (97 to 99 percent tin/1 to 3 percent copper) alloys, particularly for drinking water systems.

More Miscellaneous Uses:

·        Gas-tight sealing of metal gaskets.  Tin’s ductile properties form an airtight bond under crimped and bolted pressure, providing a stable surface for elastomer gaskets.

·        An Anti-Galling component in sliding parts.

·        Major users include automotive, instrumentation, and electrical connectors.

·        Tin is fast becoming the metal of choice to replace products typically made with Lead, such as wheel balancing weights, ammunition, and lead solder, and will even be used in the production of coins for the European Union.

 

 


 

Element

Spec. Grav.

(Rm. Temp)

Atomic Weight

Density (g/cm3)

Melt. Pt. (°F)

Hardness (kg/mm2)

Thermal Conductivity  (Btu/hr ft °F)

Elect. Resistivity (microhm-cm)

Tin

7.31

118.69

6.5

449

10

37

11.0

Gold

5.32

196.967

19.32

1945

50

182

2.35

Silver

10.50

107.868

10.5

1760

60

247

1.59

Copper

8.96

63.546

8.94

1983

80

230

1.673

Aluminum

2.70

26.9815

2.699

1220

30

137

2.655