1908 – The Societatea de reparatii foraj (Drilling Repair Company) was established, as a repair workshop for oilfield equipment, employing about 50 workers who executed repairs of tools used in the oil extracting industry.

1913 – The Societatea Creditul Petrolier (Oil Credit Company), which exploited a part of the oil reservoirs in Prahova, became the owner of the Societatea de reparatii foraj (Drilling Repair Company). Lands are purchased and new workshops and attached sections are built. The activity of the workshop is developed gradually, so that its object of activity becomes more complex, by repair of the equipment for well exploitation and manufacturing of spare parts necessary at the drilling sites.

1916 – Romania is involved in World War I and the Company is requested to contribute to the war necessities. All the workshops will be updated to face the large working volume.

1919 – After the war was over, there was an increased demand of oilfield equipment, which imposed the preparation of new production spaces and endowment with new equipment.

1922 – The Societatea Creditul Petrolier (Oil Credit Company) is bought by Grupul Industrial Concordia (Concordia Industrial Group), a strong industrial consortium, including activities for well drilling, oil extraction and transportation, manufacturing and repair of oilfield equipment. The Company is called Departamentul Uzinele Metalurgice Ploiesti (Metallurgical Works Department of Ploiesti) and usually Atelierele Ploiesti (Ploiesti Workshops). The Company develops fast in all its fields of activity. It reaches an area of about 16 hectares and a number of 475 employees.

1927 – the completely equipped Concordia-type drilling rig is designed and built, which represents a national premiere.

1933 – the world economical crisis lays its print upon the Company’s development. Still, the production stagnated at a level that allowed its existence. After the crisis was surpassed, the factory continued to be updated, they bought new equipment and employed new personnel.

1938 – with the beginning of World War II, the Grupul Concordia (Concordia Group), besides its traditional production of oilfield equipment, began to manufacture armament and components for the Army. During the war, the industrial buildings and technical workshops were destroyed, the Company suffering major losses.

1945 – After the war the damaged production capacities and annexes are redesigned and new industrial units are built.

1947 – The nationalization takes place and the property of Concordia Departamentul Uzinele Metalurgice Ploiesti (Concordia Metallurgical Works Department of Ploiesti) goes to the State; its name changes into Uzina 1 Mai – Ploiesti (1 MAI WORKS – Ploiesti). Starting with this year, Romania embarks upon an economical development of Soviet type. This system will be applied till 1955.

1950 – They start series manufacturing of equipment and rigs for oil drilling and extraction, according to foreign documentation; then they use Romanian designs, supplied by the Design and Research Institute for Oilfield Equipment (IPCUP), founded in 1955. The manufacturing profile of the enterprise covered the main rigs and plants for oilfield equipment, necessary for the oil extraction industry, except the tubular goods.

1964 – Intreprinderea 1 Mai Ploiesti (1 Mai Works, Ploiesti) obtains the first great international success with 3DH-250 drilling rig, receiving the gold medal at the International Fair of Leipzig.

1966 – At the International Exhibition of Argentina, the drilling rigs produced by Intreprinderea 1 Mai Ploiesti (1 Mai Works, Ploiesti) achieve the depth record of 5300 m;

1966 – The blow-out preventer and the hydraulic control installation are produced, as an absolute premiere.

1968 – The F-400 and 4DH-400 drilling rigs, produced by Intreprinderea 1 Mai Ploiesti (1 Mai Works, Ploiesti) obtain the depth record of 7050 at the Fair in the Democratic German Republic.

1973 – The Enterprise obtains the first place at the International Fair of Brno with the F-320 drilling rig, designated to drilling to 6000 m depth.

1974 – Besides oilfield equipment, Intreprinderea 1 Mai Ploiesti (1 Mai Works, Ploiesti) will also build metallurgical platforms and mining equipment.

1977 – The Enterprise is placed on the second place in the world for the export of oilfield equipment. The products bearing the 1 Mai trademark are exported to many countries in Europe, South America, Africa and Asia.

1985 – The industrial crisis begins, at national level, affecting the activity of Intreprinderea 1 Mai Ploiesti (1 Mai Works, Ploiesti).

1990 – After the Revolution of 1989, the transition to a free market economy begins. Intreprinderea 1 Mai Ploiesti (1 Mai Works, Ploiesti) becomes a stock company, being registered with the Office of the Register of Commerce of Prahova County under the name of Upetrom S.A. Ploiesti.

1991 – The social-economic crisis begins, as a result of losing the market and termination of the treaties regarding the economic exchanges between the former socialist countries.

1996 – It is considered that the Company’s name is not sufficiently known on the international market and the name 1 Mai is added to its new name, the full denomination becoming SC UPETROM – 1 MAI SA Ploiesti. The economic crisis deepens, more production workshops are closed and the personnel is dismissed.

2000 – The ownership form of SC UPETROM – 1 MAI SA Ploiesti is changed, from a commercial unit with major state-owned capital into a stock company with private-owned company. Ample programs are immediately commenced for revamping and updating, new personnel is employed. Modern norms and procedures are established and a quality and development-oriented management is assured