The British Army relied upon various hand grenades during World War 1 (1914-1918), some deemed successful while others were failures. Still others were developed as interim solutions to shore up limitations of previous offerings. The No. 6 Hand Grenade series was developed along the lines of a concussion grenade, intended to disorient or shock an opponent. With the war having bogged down into Trench Warfare by the end of 1914, any and all measures to unseat an enemy were taken into account. The No. 6 series appeared in 1915 but was withdrawn from service as soon as 1917. The war would not end until the Armistice of November 1918.
Royal Laboratory engineers developed the No. 6 line and the existence of this grenade - and several others - were brought about due to the limitations inherent in the No. 1 stick grenade series which the British Army entered the war with. A timed friction-based fuse system was used and overall weight was 1 pound. Diameter reached 2.25".
Like other grenades before it, the No. 6 series was pressed into service despite reservations. In practice it proved a mixed success as its arming process usually required two persons. The grenades were also sensitive to forces that could see them detonate prematurely whether directly armed or not. These, and other wartime factors, ensured that the No. 6 held a short frontline service life.
The No. 7 grenade was more of a truer anti-personnel fragmentation hand grenade with its fragmentating body. However, this design was heavier than the No. 6 and not as well liked when attempting to dislodge enemy infantry from their holes.