The M67 grenade is a fragmentation hand grenade used by the United States military. The M67 is a further development of the M33 grenade, itself a replacement for the M26-series grenades used during the Korean and Vietnam Wars, and the older Mk 2 "pineapple" grenade used since World War I.
M67 fragmentation grenade
M69 training grenades
A grenade is an explosive weapon typically thrown by hand, but can also refer to a shell shot from the muzzle of a rifle or a grenade launcher. A modern hand grenade generally consists of an explosive charge ("filler"), a detonator mechanism, an internal striker to trigger the detonator, an arming safety secured by a transport safety. The user removes the transport safety before throwing, and once the grenade leaves the hand the arming safety gets released, allowing the striker to trigger a primer that ignites a fuze, which burns down to the detonator and explodes the main charge.
Replica WW2 Hand grenades on display
Hand grenades filled with Greek fire; surrounded by caltrops (10th–12th centuries National Historical Museum, Athens, Greece)
Mongolian grenade attack on Japanese during Yuan dynasty
Seven ceramic hand grenades of the 17th Century found in Ingolstadt Germany