A grenade is a small explosive weapon typically thrown by hand (also called hand grenade), but can also refer to a shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) 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 (sometimes called the delay element), which burns down to the detonator and explodes the main charge.
Grenades work by dispersing fragments (fragmentation grenades), shockwaves (high-explosive and stun grenades), chemical aerosols (smoke, gas and chemical grenades), fire (incendiary grenades) or a jet of molten metal (anti-tank grenades). Their outer casings, generally made of a hard synthetic material or steel, are designed to rupture and fragment on detonation, sending out numerous fragments (shards and splinters) as fast-flying projectiles. In modern grenades, a pre-formed fragmentation matrix inside the grenade is commonly used, which may be spherical, cuboid, wire or notched wire. Most anti-personnel (AP) grenades are designed to detonate either after a time delay or on impact.
