Metals are often compounded with each other to obtain various properties not possessed by the metals themselves, such as: (1) Reduction of melting point to something lower than that of one or more of the constituent metals. (2) To increase the strength or toughness. (3) To obtain a different colour. (4) To resist oxidation, or corrosion of sea and other water. (5) To obtain a hardened metallic compound. (6) To facilitate the flow of metal in forming sound castings.

The following is a list of the more important alloys: -

Description

Copper

Zinc

Tin

Properties

Best Brass ......

72

28

-

Very malleable.

Ordinary Brass

66.6

333

-

Muntz or Yellow Metal

60

40

-

Rolls hot, resists corrosion.

Dutch Metal

84

16

-

Highly malleable.

Bronze Coinage

95

1

4

Gun Metal

90

-

10

Very tough.

Speculum Metal

66.6

-

333

Takes high polish.

Britannia Metal

1.8

-

92

and Antimony 6.2.

Babbit's Metal

1

-

50

" " 5.

Delta and Aich's Metal

55-60

38-44

with 1.5 to 4 of Iron.

Pewter Plate

2

-

89 with Antimony 7 and Bismuth 2.

German Silver

60

25

with Nickel 15.

Common Pewter often consists of Lead and Tin alone.