(Chem. symbol: Cu). A lustrous, reddish brown metallic element which is malleable, ductile, and an excellent conductor of heat and electricity. It is extremely tough, but very ductile. When heated to just under its boiling point, the metal becomes so brittle that it can be powdered. Copper is very resistant to atmospheric oxidation and corrosion. Copper has an atomic weight of 63.5; atomic number, 29; melting point, 1082°C (1980°F); boiling point, 2310°C (4190°F); specific gravity, 8.4.

Copper is widely used for electrical conductors and for the manufacture of electrical equipment. It is used in water tubing, valves, fittings, heat exchangers, chemical equipment and bearings. Copper is the electrical conductivity standard of the engineering world, with a rating of 100% IACS (International Annealed Copper Standard). Copper and most copper alloys can be welded, brazed and soldered.