A new steel company, Bokaro Steel Limited (Bokaro Steel Plant), was incorporated on 29 January 1964 to construct and operate the steel plant at Bokaro. The 1 MT phases of Bhilai and Rourkela Steel Plants were completed by the end of December 1961. The 1 MT phase of Durgapur Steel Plant was completed in January 1962 after commissioning of the Wheel and Axle plant. The crude steel production of HSL went up from 1.58 MT (1959–60) to 1.6 MT. The second phase of the Bhilai Steel Plant was completed in September 1967 after commissioning of the Wire Rod Mill. The last unit of the 1.8 MT phase of Rourkela – the Tandem Mill – was commissioned in February 1968, and the 1.6 MT stage of Durgapur Steel Plant was completed in August 1969 after commissioning of the Furnace in SMS. Thus, with the completion of the 2.5 MT stage at Bhilai, 1.8 MT at Rourkela, and 1.6 MT at Durgapur, the total crude steel production capacity of HSL were raised to 3.7 MT in 1968–69 and subsequently to 4 MT in 1972–73. IISCO was taken over as a subsidiary in 1978 and later merged in 2006.