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Some non-ferrousmetals do not contain iron, such as copper, nickel and tin. Other metals and alloys in which iron may be present but not in the principal proportion are also classed asnon-ferrous.
Non-ferrousmetals are more expensive than ferrous ones. They are used, therefore, only where special properties are required. Mostnon-ferrousmetals have better resistance to corrosion than steel; they are usually more easy to cast and to work, some of them have especially high thermal and electrical conductivity or light weight, etc.
The metals most frequently used to make non-ferrousmetal casting are copper, tin, zinc, lead, nickel, gold and aluminium.
Copper is a reddish-brownmetal. It has very high electrical conductivity and highcorrosion-resistantqualities. Its electrical conductivity is higher than that of any other metal except the much more expensive silver. Copper is used for making electrical contacts and wires, pipes, telephone cables, etc.
Zinc is a hard, brittle, bluish-whitemetal that is employed in the pure form as sheet zinc.
Lead is a very heavy bluish-greymetal which is very soft. This metal is highly resistant to corrosion, but its strength is so low that it must be supported by a core of some other metal. Lead is used for lining pipes, acid tanks, etc.
Aluminium is a soft silvery white metal. It is light in weight, has high corrosion-resistantqualities and is used for automobile and airplane parts as well as for making differentlight-weightobjects-frames,chairs, etc.
Tin is a silvery, corrosion-resistantmetal. It is hardly used in pure form, but is employed as an alloying element.
Nickel is a hard silvery metal. It has high corrosion-resistantqualities and is used for plating iron, steel, brass, and other base metals. The thickness of nickel is often 0.0003 in. for plating on brass and 0.001 in for plating on steel.
The above-mentionednon-ferrousmetals may be mixed in various proportions to form many alloys