Incendiary Grenade
In Unusual Weapons
Incendiary grenades produce intense heat by means of a chemical reaction. The body is practically the same as that of a smoke grenade. The filler is 600 to 800 grams of thermate (TH3), which is an improved version of the World War II-era thermite. The chemical reaction that produces the heat is called a “thermite reaction.”
In this reaction, aluminum metal and iron oxide (rust) react to produce iron and aluminum oxide. This reaction produces a tremendous amount of heat, burning at 2200 degrees Celsius (4000 degrees Fahrenheit). A thermite grenade can melt together the metallic parts of an object. This makes incendiary grenades such as the AN-M14 useful for destroying weapons caches, artillery units, and vehicles. Other advantages of thermite include its ability to burn through a 1/2-inch (12.7 mm) steel plate, and that an external oxygen source is not needed to sustain the reaction.
Because of this, an AN-M14 can burn underwater.