The Indian Iron and Steel Company founded in 1918 and the Steel Corporation of Bengal founded in 1937 merged under the former trade name in 1952.
It has three separate plants at Hirapur (about 6.5 km south of Asansol), Kulti (about 16 km west of Asansol), and Burnpur (about 5 km south-west of Asansol). These three are integrated under one unit with their location along Kolkata-Asansol rail-line about 227 km north-west of Kolkata. The management of IISCO was taken over by the Government of India in July 1972.
Steel plants obtain iron ore from its captive mines at Gua. A treatment plant with a capacity of 18.3 lakh tonnes of ores per year has been built near the mines. The supply of coal is received from the collieries of Ramnagar (3.2km from Kulti), Noonodih and Jitpur (Jharia coal field).
The limestone is obtained from Paraghat and Baraduar on the Eastern Railway; manganese from Jharkhand, Bihar, Orissa and Madhya Pradesh; quartz from the Kharagpur hillsnear Munger; fireclay from Kumardhubi Fireclay and Silica Works (Singhbhum district); cheap hydro-electricity from the D.V.C.; and water from the Damodar river. The company also has the proximity of Kolkata city (for marketing) and Kolkata Port.
IISCO has annual capacity of producing 10 lakh tones of steel. During 1997-98 it produced 4.08 lakh tones of pig iron, 3.60 lakh tones of crude steel and 3.77 lakh tones of saleable steel. The plant at Kulti only produces pig iron while Hirapur and Burnpur manufacture both pig iron and steel.
The products are similar to TISCO including rail sleeper, girder, steel sheets, pipers etc. A number of auxiliary units have come up near the plant including the Eastern Light Castings at Kulti, the Indian Standard Wagons at Burnpur and the Chittaranjan Locomotives at Chittaranjan. Major part of the production is used for rails, track parts and picket posts, etc.