The knife is one of the oldest human weapons, and it is still used both as a tool and for combat. The U.S. Military uses several knives and knife-type weapons, including dual-use knife-bayonets,with the major user being the two services most concerned with ground combat: the U.S. Army and the U.S. Marine Corps. By and large, the Air Force, Navy and Coast Guard adopt Army and Marine knives for their purposes.

A military knife should be unmarked and unreflected. This prevents giving the enemy unwanted intelligence on you unit's position if the knife is lost and prevents making you a target if an enemy catches the sun's glare reflecting off your knife. A bead blasted or coated military knife is preferable to a shiny one.
When choosing a army knife, military personnel usually choose fixed blades for their blade strength and easy accessibility. There are many styles of fixed blade army knives, bench-made knives, almar knives, cold steel knives. These military knives are usually designed to serve more than one function, which is a perfect way to lighten what you have to carry.
Military uses several knives and knife-type weapons, including dual-use knife-bayonets, with the major user being the most concerned with ground combat the army/navy/commando knives for their purposes.

As you pack up the tent, gather snacks, food and drink, certain survival resources and tools will come in handy depending on the types of activities you wish to enjoy while roughing it in the wild. Sometimes overlooked during the packing of supplies, a military knife allows individuals to perform a variety of army forces related tasks that range from survival to food preparation.

during the World War II was the Fairbairn-Sykes Fighting Knife. This was the double-edged knife with a special grip developed by William Fairbairn. It was issued to the British commandos, Canadian soldiers and the SAS to protect them in hand-to-hand combat. The knife is often compared to a stiletto but the comparison is misleading because the stiletto was a stabbing knife.

The Canadian military knife is very popular with collectors mainly because of its association with the commando Regiment and in fact it was very popular with the British and a commemorative knife was created in solid Gold and placed in the memorial at Westminster Abbey.
Unique Design of the Military Knife used by Canadians in World War II

This Canadian military knife designed by Fairbairn Sykes was for use in surprise attacks and combat fighting. It has a slender blade which could pierce the rib cage, leaving a deadly blow. The handle allows for precise grip and combined with the double-edged blade makes the perfect combination to protect someone who is involved in one-on-one hand-to-hand combat. The two main features while designing this combat knife were keenness and balance.

Combat trainers would have you know that there is no more deadly weapon than the knife when you're fighting at close range. The Canadian combat knife used in World War II was also designed to protect the owner. But it is supposed to be easy to handle and fits easily in the hand of the user, without being so heavy that it drags the knife. The blade was designed with sharp cutting edges and a good stabbing point which aims to make a clean cut in the artery causing the victim to bleed and die quickly.

The combat knife used during World War II by the Canadians was created in several patterns. It takes the original design of the Shanghai knife which is only 5.5 inches long at the blade. The first pattern knives have a 6.5 inch blade with a flattened ricasso which is missing from the original design and still unexplained by the manufacturer.

They also have a slightly longer blade which is less than 7 inches and finished with a 2 inch wide oval shaped cross guard. The patterned grip is knurled and the word England is stamped on the handle side of the cross piece.

The third pattern of this knife has a different handle which was designed to include a ring grip but this was not favored by the designer because it made the weapon harder to hold when it became wet. However, the manufacturer continued to make this knife because it is very easy to manufacture.

The reason the blades are so long is that during combat fighting with opponents bearing thick clothing, the long blade would ensure that it would penetrate the clothing and then the flesh delivering a fatal wound to the victim.