Combat knife

The Combat Knife, occasionally referred to as the Close Quarters Combat Weapon System, is a multi-purpose infantry-sized knife used by the United Nations Space Command.

Overview
The UNSC's multi-purpose combat knife has a 20 centimeter (7.9 inch) blade made of high carbon steel, an anti-flash non-reflective titanium carbide coating, edge coated for corrosion resistance and is 43.3 centimeters (1.42 feet) when sheathed. All UNSC troops are issued with a combat knife for field and utility uses, as well as a backup weapon for desperate situations. It is also balanced for throwing.

History
Knives have been used in battle almost since the dawn of warfare, first as a sharp piece of rock, and then metal proved effective during a period of time where projectile weapons were not readily available. The combat knife later branched off and became a sword, while others used daggers. For thousands of years, knives and swords have been a weapon of choice for soldiers. Even after the invention of the firearm, knives were still used as bayonets for close-quarters-combat and in event of enemys cavalry charge. Sabers were still issued in World War I. As war tactics shifted from trench warfare to attrition warfare, knives became last-resort weapons or simple tools used for cutting food up to making fire wood. By 2553, the UNSC still uses knives, showing that such an easily accessible and created weapon still runs strong even thousands of years later.

Appearances
A larger version of the combat knife, called the machete, was intended to be used in pre-releases versions of Halo: Combat Evolved build, but was cut before it made it into the final game, replaced with the game's use of melee attacks from any weapon.

In Halo 2, combat knives appear on the lower backs of Orbital Drop Shock Troopers.

The MJOLNIR CQB chest permutation in Halo 3 sports a sheathed combat knife attached to the left chest section. It cannot be drawn or used, as it is purely ornamental.

In Halo Wars, Sergeant John Forge uses his combat knife, which he has nicknamed "Lucy", to wound the Arbiter before killing the Sangheili with his own energy sword.

In Halo 3: ODST, Edward Buck can be seen wearing a combat knife on his chest plate, which he uses to kill a Jiralhanae Chieftain by stabbing him in the neck, afterwards casually flicking the alien's blood off its blade.

In the Halo Legends episode The Package, Frederic-104 uses a two combat knives which are remarkably different from the standard-issue model. The blade is shaped similarly, but the handle has three circular holes cut out of it, most likely to reduce the weapon's overall weight. The back edge is serrated. These knives are stored in the shoulder pauldrons of Frederic's Mark IV MJOLNIR armor.

In the Halo: Reach world premiere cinematic, Emile-A239 is seen sharpening a kukri, a traditional Nepalese knife, against his shoulder plate. In-game, knives are used to perform special extended animation sequences called "assassinations" by holding down the melee button when behind an opponent.

Trivia

 * Frederic-104 possesses particular skill with combat knives, and is rather fond of their use.
 * In Halo: Reach, when performing third-person assassination sequences, the knife on the player character's armor is not used. Instead, a different is spawned in the character's hand while the other knife remains in the SPARTAN's chest scabbard.

Links
Internal
 * Curveblade
 * Energy Cutlass
 * Jiralhanae Combat Knife

External
 * Wikipedia 's article on Bayonet
 * Wikipedia 's article on Combat Knife