Ka-Bar

A Ka-bar is the 7-inch fighting and utility knife used by the US Marines in World War II, and has been carried into battle by generations of Marines since. more...

The knife itself is a Bowie knife with a seven-inch (17cm) blade originally designed as a hunting knife around 1890, and would have been considered unremarkable at that time. In 1942, soon after the United States' entry into World War II, Americans soldiers experienced the problematic nature of "US 1917/1918" stilettos and "Mark I" daggers that they were issued initially, and realized the need for knives suited to trench warfare, and the Ka-Bar design was chosen from a catalog of hunting gear. The Marines bought a great many knives of myriad designs from a large number of suppliers during the war, but it was the Ka-Bar that was most common and popular. It was chosen for continued purchase and issue after the war was over. The sole change made to the design before it was manufactured for issue was that blade, guard, and pommel were all finished in a non-reflective matte black or grey phosphate finish instead of the brightly polished steel of the original. Marines today often give the blades, guards, and pommels of their knives a few coats of non-reflective matte black spray paint to reduce reflected light and give them a little more protection against saltwater corrosion. Ka-bar today makes Army and Navy versions as well. They are virtually indentical to the Marine version except for different initials at the bottom of the blade and different symbols on the sheath. Its moderate carbon and low chromium steel mixture allows the blade to hold an edge very well. The knife's success can be attributed to its balance of weight, length, and price.

Read more at Wikipedia.org