Question

which metal is often called the back bone of modern industry​

Answer 1

Iron and steel industry

Iron and steel industry is often referred as the backbone of the modern industry because all the tools, machineries, equipments, material for construction, etc. are made up of either iron or its alloys.

Answer 2

Iron and Steel Industry is often called the backbone of modern industry. Almost everything we use is either made of iron or steel or has been made with tools and machinery of these metals. Ships, trains, trucks, and autos are made largely of steel. Even the safety pins and the needles we use are made from steel.