• This is a feeder industry whose products are used as raw material for other industries.• The inputs for this industry include raw materials such as iron ore, coal and limestone, along with labour, capital, site and other infrastructure.• The process of converting iron ore into steel involves many stages.→ The raw material is put in the blast furnace where it undergoes smelting.→ It is then refined.• The output obtained is steel which may be used by other industries as raw material.Iron and Steel• Steel is often called the backbone of modern industry.→ Daily use tools, Ships, trains, trucks, and autos are made largely of iron or steel.• Features of Steel:→ Steel is tough and it can easily be shaped, cut, or made into wire.→ Special alloys of steel can be made by adding small amounts of other metals such as aluminium, nickel, and copper.→ Alloys give steel unusual hardness, toughness, or ability to resist rust.Timeline of Iron and Steel industry's location• Before 1800 A.D. iron and steel industry was located where raw materials, power supply and running water were easily available.• Between 1850 to 1900 A.D., the  ideal location for the industry was near coal fields and close to canals and railways.• After 1950, iron and steel industry began to be located on large areas of flat land near sea ports because by this time steel works had become very large and iron ore had to be imported from overseas.• Location of iron and steel industry in the world: Germany, USA, China, Japan and Russia.• Location of iron and steel industry in India: Bhilai (Chhattisgarh), Durgapur, Burnpur (West Bengal),  Rourkela (Odisha), Bokaro, Jamshedpur (Jharkhand).• Other important steel centres: Bhadravati and Vijay Nagar in Karnataka, Vishakhapatnam in Andhra Pradesh, Salem in Tamil Nadu.Jamshedpur• Before independence, Tata Iron and Steel Company Limited (TISCO) was only one iron and steel plant in the country which was privately owned.• After Independence, the government set up several iron and steel plants.→ TISCO was started in 1907 at Sakchi, near the confluence of the rivers Subarnarekha and Kharkai in Jharkhand. Later on, Sakchi was renamed as Jamshedpur.Why Sakchi was chosen to set up the steel plant• This place was only 32 km away from Kalimati station on the Bengal-Nagpur railway line.• It was close to the iron ore, coal and manganese deposits as well as to Kolkata, which provided a large market.• TISCO, gets coal from Jharia coalfields, and iron ore, limestone, dolomite and manganese from Odisha and Chhattisgarh.• The Kharkai and Subarnarekha rivers ensured sufficient water supply. Government initiatives provided adequate capital for its later development.Pittsburgh• It is an important steel city of the United States of America. Why iron and steel industry developed in Pittsburgh• The raw material such as coal is available locally, while the iron ore comes from the iron mines at Minnesota, about 1500 km from Pittsburgh. → Between these mines and Pittsburgh, Great Lakes waterway is present which is one of the world’s best routes for shipping ore cheaply. → Trains carry the ore from the Great Lakes to the Pittsburgh area. → The Ohio, the Monogahela and Allegheny rivers provide adequate water supply.• Today,, Large steel mills are located in the valleys of the Monogahela and Allegheny rivers above Pittsburgh and along the Ohio River below it. • Finished steel is transported to the market by both land and water routes.• Other factories present in Pittsburgh area use steel as their raw material to make many different products such as railroad equipment, heavy machinery and rails.