There are several varieties of hand grenades designed for many purposes. All of these grenades can be broadly classified into six general types: fragmentation, illumination, chemical, incendiary, l smoke, and practice and training grenades.

Fragmentation Grenades

Fragmentation grenades are used to produce casualties by the high-velocity projection of fragments from the grenade case. The M67 fragmentation grenade (fig. 12-1) is the standard grenade used by Seabees. It has a smooth, sheet-metal body and is shaped like a ball. Its outer case is lined on the inside with a serrated wire coil. It is filled with 6.5 ounces of an explosive, known as Composition B, and uses a detonating type of fuze. When the detonator causes Composition B to explode, fragments of the body and fuze assembly are hurled in all directions. The M67 weighs 14 ounces and the average man can throw it 40 meters. The effective casualty-producing radius is 15 meters.

Illuminating Grenades

The MK1 (fig. 12-2) is the only illuminating grenade currently available. Its main use is to illuminate

Figure 12-1.-Fragmentation hand grenade, M67.

Figure 12-2.-Illuminating hand grenade, MK1.

Figure 12-3.-ABC-M25A2, CS riot control hand grenade.

terrain in night operations. It provides about 55,000 candlepower for a period of 25 seconds. The MK1 grenade may also be used as an incendiary grenade to start fires in dry grass, leaves, or brush. When the two halves of the body are separated by the burning of an illuminating charge, they project with considerable velocity. Friendly forces should take cover until the illumination can be seen. Once the safety pin of this grenade has been removed, the grenade is armed and MUST be thrown. Do NOT attempt to replace the safety pin.