The Mk 1 grenade (sometimes spelled Mk I) is a fragmentation

hand grenade A grenade is a small explosive weapon typically thrown by hand (also called hand grenade), but can also refer to a Shell (projectile), shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) or a grenade launcher. A mod ...

used by American forces during

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

. According to its designers, it was to be the "simplest", yet most "fool-proof", grenade ever made. However, some major problems appeared when the grenade was used in the field. It was retired from service before the war ended, replaced in 1918 with the improved

Mk 2 grenade The Mk 2 grenade (initially known as the Mk II), also nicknamed the Pineapple is a fragmentation-type anti-personnel hand grenade introduced by the U.S. armed forces in 1918. It was the standard issue anti-personnel grenade used during World ...

used through

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

Overview

The Mk 1 is a time-fused fragmentation grenade and has 32 serrations on it. To start the fuse, the user has to pull the safety pin, then push off the cap on top of the grenade. Right before throwing, the user has to move the switch on the lever away from the grenade in order to start the fuse.

History

When American forces entered World War I, they lacked a fragmentation grenade of their own. American forces often received either the

Mills bomb "Mills bomb" is the popular name for a series of British hand grenades which were designed by William Mills. They were the first modern fragmentation grenades used by the British Army and saw widespread use in the First and Second World Wars ...

or the French F1 grenade. When it came time to make a grenade, American designers looked to the F1 grenade for inspiration. In 1917, the Mk 1 grenade was created. However, it became apparent that the Mk 1 grenade was quite difficult to use in the field. The grenades were often not ignited properly before being thrown, and enemies would return the grenade, this time properly lit.
/ref> The Mk 1 was immediately recalled and production stopped. It was replaced in 1918 with the improved

used through

Variants

Mk. IA1

The Mk. IA1 was an inert cast-iron training grenade. It has a simulated fuze with a removable pin and safety lever. They were manufactured for a brief time during World War I to train troops on how to initiate and throw the Mk. I and Mk. II fragmentation grenades. Early in the United States’ entry into

, a number were produced as training aids in 1942. Its markings consist of a black body with a narrow white band around the top.

References

External links

More Mk 1 grenade pictures and a picture of the training model
{{WWIUSInfWeaponsNav World War I infantry weapons of the United States Hand grenades of the United States Fragmentation grenades Weapons of the Philippine Army Weapons and ammunition introduced in 1917