Mk 1 grenade

The Mk 1 grenade (sometimes spelled Mk I) is a fragmentation hand grenade used by American forces during World War I. 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, and it was retired from service before the war ended.

Country Name Origin Year
United States of America 1917
Country Name Operational Year Retirement Year
United States of America 1917 1918 View

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.

When American forces entered World War I, they lacked a fragmentation grenade of their own. American forces often received either the Mills bomb or the French F1 grenade. When it came time to make a grenade, American designers looked to the F1 grenade for inspiration.[citation needed] 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. The MK 1 was immediately recalled and production stopped.

The Mk 2 design was created as an improved Mk 1 and was used before World War I ended. Unused Mk 1 parts were used to make Mk 2 grenades while factories were retooled to make the Mk 2.

Type Time-fused grenade
Place of origin  USA
Service history
In service 1917-1918
Used by United States
Wars World War I
Production history
Designed 1917
Produced 1917-1918
Timed Friction Fuse

End notes