During the earliest days of the war the British and Empire armies were seldom issued grenades, but the need for such weaponry became apparent once it was clear to all that trench warfare was going to be the norm. The earliest grenades (improvised by both sides) were simply food tins that were jam-packed with an explosive mixed with nails, glass shards and bits of iron. By 1915 grenade production was in full swing and British historians have estimated that throughout the course of the war on the Western Front, British and Commonwealth forces had used fifteen million hand-grenades.
The following article concern a British shrapnel grenade that is of the heavy friction pattern.
Click here to read about French grenades of W.W. I.
Click here to learn about the timing fuses designed for W.W. I shrapnel shells.