1811Founding of Rolling Mill.
1885Establishing a Share Company of Zakłady Ostrowieckie.
1886Transformation of the company into the "Towarzystwo Akcyjne Wielkich Pieców i Zakładów Ostrowieckich".
1889Commissioning of the first open hearth furnace with a capacity of 15 t.
1890Launch of a medium rolling mill and a new mechanical workshop.
1891Completion of the construction of the iron foundry; start-up of the second open hearth furnace..
1892Start-up of the third open-hearth furnace, start-up of a workshop for machining wieghing parts and finishing railway axles.
1893Construction of foundations for the blast furnace no. 2 with Cowper heaters (the first furnace was built during the construction of the rolling mill); the settlement of the first apartment block intended for employees of the plant.
1897Doubling the number of people living on the factory premises from 5 thousand (in 1890) up to 10 thousand.
1898Commissioning of a 500 HP power plant, first smelting of steel from open-hearth furnace No. 9.
1899Commissioning of open-hearth furnaces no. 10 and 11, universal plate rolling mill.
1900Start-up of the 12 open-hearth furnace (with a capacity of 25t), start of production in a large rolling mill; commissioning of the factory infirmary building.
1936Establishment of the Central Industrial District - the most important industrial investment in the times of the Second Polish Republic; dynamic development of Rolling Mill.
1939Joining Reichswerke AG fur Berg- und Huttenbetrieb Hermann Goring – a concern owned by the Third Reich.
1940Development of production and increase of employment to 4634 workers.
1942Production at the level of: pig iron 4100-4300 tons per month, steel 5870-7000 tons per month.
1944Disassembly of machines and devices in some departments.
2003Division of Zakłady Ostrowieckie into an old and a new part.
2015Start of operations of Walcownie Ostrowieckie Wost S.A.