Fighting knife the Kukri, a broad-bladed, curved general-purpose cutting tool and weapon with Indian origins. In other countries the machete or Filipino Bolo were often used as fighting knives by indigenous military or paramilitary forces. Colonial powers that encountered these general-purpose weapons used as fighting knives during a military campaign occasionally adopted them in turn for use by their own military forces, as exemplified by the U.S. Army's Model 1910/17 "Bolo" brush-clearing knife, which would be later pressed into service as a fighting knife in both World Wars. In World War I, military use of the fighting knife saw the introduction of
Knife sharpening one source for honing stones, which are traditionally used with water or honing oil. India is another traditional source for stones. Ceramic hones are also common, especially for fine grit size. Japanese water stones (both artificial and natural) come in very fine grits. Before use, they are soaked in water, then flushed with water occasionally to expose new stone material to the knife blade. The mixture of water and abraded stone and knife material is known as slurry, which can assist with the polishing of the knife edge and help sharpen the blade. Generally, these are more costly than oilstones.