The history of Australia´s largest integrated plants dates back to 1928 when Australian Iron & Steel was established to take over the original Hoskins Iron & Steel business. Charles Henry Hoskins had started iron production in Lithgow in 1908 and moved production to the suburb of Wollongong, a site called Port Kembla.

Thus in 1932 the first blast furnace was fired, followed by three open-hearth furnaces, a 27/28" mill, a 36" mill, a rail mill and a structural mill.

In 1935 the company merged with Broken Hill Proprietary Co Ltd, later known as the BHP. Dynamic technological developments were following:

1937 - coke plant
1938 - no.2 blast furnace
1939 - two additional OH furnaces and a billet mill
1943 - expansion by two more OH furnaces

During the Second World War the production was fully subordinated to the needs of the armaments industry. After the end of the war, there was a shift towards flat steel products and by the mid 1950s Port Kembla Ironworks claimed the highest output of any steelplant in the UK or the Commonwealth.

The post-war development is following:

1952 - no.3 blast furnace
1955 - strip mill
1957 - sinter plant
1959 - blast furnace No.4
1963 - heavy plate mill
1972 - blast furnace No.5 and LD converter shop commissioned
1978 - first continuous slab casting plant, gradually displacing ingot production
1983 - construction of the third oxygen converter, shutdown of the open hearth shop
1996 - blast furnace no.6

In 2002 the BHP steel division was broken into a number of companies. The Port Kembla plant became independent and BlueScope Steel took over the whole site.

Blast furnace No.6 was decommissioned in 2011 due to the unfavourable market situation and is currently planned to be relined. This will be the last blast furnace in New South Wales as BlueScope slowly prepares for a full transition to hydrogen steelmaking.