"F1" is used to designate a variety of hand grenades of modern design and of the 20th century. The Soviet Union used the F1 designation for its standardized anti-personnel fragmentation infantry hand grenade spawned out of necessity during World War 2 to help combat the scourge of the Nazi invasion of the Motherland, begun through Hitler's "Operation Barbarossa", in June of 1941. As such, the Soviet defense industry awoke and began a massive program to push the German Army back to Berlin. The F1 proved quite effective in its intended role and was, itself, based on the F1 grenade of French origin.
Design of the Soviet F1 was rather straight-forward. The external steel casing was ribbed to ensure a solid hand hold. The fuse was integrated to the grenade body and actuated by manual removal of a safety component. Range was as far as a soldier could throw it and the blast radius within was rather standard - 15 meters for optimal effect and out to 30 meters peripheral. Additionally, shrapnel could reach much further than that due to the explosion. The explosive filling was a Trinitrotoluene (TNT) base of 60 grams. The entire F1 unit weighed in at 600 grams and featured a diameter of 55 millimeters. The fuse could feature a delay of 0 seconds to 13 seconds, this variable nature ensuring that it could be both thrown within a window of relative safety, or used as a hidden boobytrap explosive of sorts, this triggered by some external means depending on the setup.
The F1 saw extensive service with the Red Army in World War 2. It was quantitatively produced to the point that it was also exported out to Soviet satellite nations and allies in the post-war world, ensuring its place in the annals of military history. Its reach was such that the weapon can still be found in the far off places of the world today, a testament to its effective design and global reach.