The F-1 grenade is a hand grenade mass-produced by France during and after WW1, used en masse in the majority of European countries throughout the First World War and Second World War. It is said to be the forefather of the modern defensive grenade.
The F-1 grenade was first put into mass production by the French State in 1915 during the First World War. In May 1915 the first of the F1 grenades (fusante №1) appeared in the French Military, in limited quantities. This new weapon inherited from the experience of the first months of the war: the shape was made to be more modern, with an external grooves pattern for better grip and easier fragmentation. The second expectation proved deceptive, since the explosion in practice gave no more than 10 fragments (although the pattern was designed to split into all the 38 drawn divisions). The design was proved to be very functional, especially due to its stability compared to other grenades of the same period. Later the Fusante №1 was used en masse by many foreign armies in the period from 1915 - 1940. The F-1 grenande has been used as a basis for the development of many other grenades by different nations, including the US and the USSR. It is the most recognisable grenade of the 20th century.
The F-1 was very widespread during the first half of the 20th century, used by armies of France, Great Britain, United States, Imperial Russia, Soviet Russia, Finland, and others. Overall more than 60,000,000 (sixty million) grenades were produced over 25 years, from 1915 - 1940.