An 81-mm mortar is a medium-weight mortar. It is a smooth-bore, muzzle-loading, high-angle-of-fire weapon used for long-range indirect fire support of light infantry, air assault, and airborne units across the entire front of a battalion zone of influence.[1][2]
Many countries use or have used an 81-mm mortar in their armed forces. Examples are:
Warsaw Pact countries and China use a similar 82 mm caliber for the same purpose.[2]