Bayonets
A bayonet is a knife-shaped weapon designed to fit a muzzle of a rifle barrel. The bayonet's mission is to defeat the enemy in hand-to-hand combat. In addition, bayonets can be used as utility and general field knifes. As of 2010, the U.S. Army employed the M9 bayonet, which entered army service in 1987. The M9 bayonet fits the M16 series rifle and the M4 series carbine. Together with its scabbard, the M9 can also be used as a wire cutter and as a saw.
Fighting Knifes
A fighting knife, also known as a combat knife, is in many ways similar to a bayonet. Still, while most bayonets can be used as a knife, fighting knifes cannot be readily used as a bayonet, as most aren't designed to fit a rifle barrel. Fighting knifes come in a variety of forms. Combat knifes are typically used not only in hand-to-hand combat, but also as utility tools, for example to clear foliage or chop branches for cover.
Machete
A machete is a large cleaver-like tool used in many countries for agricultural purposes. Still, machetes are often used as a military weapon, and not just in African countries. The U.S. Army uses machetes with 18-inch blades for combat operations in the jungle. Machetes of this size were also used by U.S. military forces in the Vietnam War.