Question

Among pig iron and wrought iron, which is used for making tools? Why?

Answer 1

Hint: Pig iron is brittle, hard and non-malleable. Wrought iron is ductile, malleable, high tensile strength than pig iron and can be heated again and again so that one could work on it so as to give it shape. Wrought iron is more stable and strong.

Complete step by step answer:
The term iron is used for different materials which contain a high percentage of iron in elemental form. These are pure iron, wrought iron, cast iron, pig iron, etc.
 On the basis of properties among pig iron and wrought iron, wrought iron is used for making tools.
Pig iron:
Pig iron has a high content of carbon along with a slight percentage of manganese, sulphur, silicon and phosphorus.
It cannot be used for immediately as they are very raw and they require a further melting process to remove impurities like coke, lime, etc.
Pig iron is hard, wear resistant, fairly fusible and very brittle.
It has a very low melting point.
Wrought iron:
Wrought iron is highly malleable and ductile material, and can be reheated a number of times.
Wrought iron is soft, ductile, magnetic, and strong with high elasticity and tensile strength.
Content of carbon is very low in wrought iron.
Wrought iron is free from impurities which make it very soft.
They are non-resistant enough to cause extreme shocks.
They are susceptible to corrosion when bare surfaces are left exposed to oxygen in presence of moisture.
From the above properties of pig and wrought iron, pig iron is not a good material for making tools while wrought has properties which make it susceptible to making tools.


Note:
Pig iron is made by melting iron, charcoal and limestone together through extreme air pressure, after the intense melting process in the furnace, pig iron is obtained.
Wrought iron is simply made by smelting the pig iron and oxidising it with iron oxide in a puddling furnace.