Why iron and steel industry called heavy industry?

The iron and steel Industry is the basic industry because:

i. All the other industries - heavy, medium and light, depend on it for their

machinery.

ii. Steel is needed to manufacture a variety of engineering goods, construction

material, defence, medical, telephonic, scientific equipment and a variety of

consumer goods.

iii. Iron and steel is a heavy industry because all the raw materials as well as finished

goods are heavy and bulky. It involves heavy transportation costs.