Fragmentation grenade

Grooved body of a Second World War-era U.S. Mk 2 grenade. The grooves covering the exterior of the grenade cause it to break into many pieces upon explosion.^{[citation needed]}

A fragmentation grenade (commonly known as a frag) is an anti-personnel weapon that is designed to disperse shrapnel upon exploding. The body is made of hard plastic or steel. Flechettes, notched wire, ball bearings or the case itself provide the fragments. When the word grenade is used without specification, and context does not suggest otherwise, it is generally assumed to refer to a fragmentation grenade.

These grenades were sometimes classed as defensive grenades because the effective casualty radius of some matched or exceeded the distance they could be thrown, thus necessitating them being thrown from behind cover. The Mills bomb or F1 grenade are examples of defensive grenades where the 30–45 m casualty radius matched or exceeded the 30 m that a grenade could reasonably be thrown. An example of offensive use is that Soviet Army paratroopers during the cold war were trained to throw fragmentation grenades from an altitude of about 100 m if the ground below them was held by enemy forces.

Modern fragmentation grenades such as the United States M67 grenade have a wounding radius of 15 m (half that of older style grenades, which can still be encountered) and can be thrown about 40 m. Fragments may travel more than 200 m.