This article includes a list of general references, but it lacks sufficient corresponding inline citations .(July 2015)
|Place of origin||United States|
|Designer||Charles A. "Mickey" Finn|
|Manufacturer||Phrobis, Buck Knives, LanCay, and Ontario|
|Length||12 in (30 cm)|
|Blade length||7 in (18 cm)|
|Blade type||Clip point|
The M9 Bayonet, officially known as the M9 Phrobis III, is a multi-purpose knife and bayonet officially adopted in 1986 by the United States. It has a 7-inch (18 cm) blade and is issued with a sheath designed to double as a wire cutter.
The M9 bayonet was designed and developed by Charles A. "Mickey" Finn at his R&D company, Qual-A-Tec.    It is a refined copy of the Russian AKM 6H3 bayonet.  He later produced it under the Phrobis III name, filling a military contract for 325,000 units. Buck Knives was contracted to make 300,000 units and sold a commercial version under their own name. Finn's designs proved extremely popular, and were widely counterfeited and sold illegally by other makers.  In 1989, Finn received U.S. Patent 4,821,356 , however, unlicensed copies continued to flow unchecked into the United States from Asia and Mexico, cutting into legitimate sales.
After the Phrobis III bayonet contract was completed, rights to the M9 reverted to the United States Army and there were many subsequent versions from other companies. It is issued by the armed forces of the U.S. and other countries, and has also been sold commercially in various versions.
Some production runs of the M9 have a fuller and some do not, depending upon which contractor manufactured that batch and what the military specs were at the time. The M9 Bayonet partially replaced the older M7 Bayonet, introduced in 1964. Although it has been claimed that the M9 may be more prone to breakage than the older M7, the M9 bayonet has a 20% thicker blade and tang (0.235" vs. 0.195") and a 75% greater cross-sectional area of steel in the blade than the M7.
The M11 knife (not strictly a bayonet as it has no mounting catch or muzzle ring; more of a revision to the Buckmaster 184/188 knife, which was the basis for the Phrobis XM-9 prototype bayonet  ), or M11 EOD is a version of the M9 specialized for explosive ordnance disposal (EOD). It has some extra features, such as a hammer pommel, but uses the same blade and sheath as the M9.
There have been five main makes of M9s: Phrobis, Buck (subcontracted by Phrobis III during the original Army contract), LanCay, Ontario and Tri-Technologies. Starting in 1987, Phrobis subcontracted Buck, finishing up in 1989. It was around this time that Buck sold commercial M9s as well, which it did up to 1997.
LanCay got its first contract in March 1992 (taking over production from Buck) for 30 (later 50) thousand knives (with General Cutlery as a subcontractor); in 1994, there was another contract issued for about 100,000 improved M9 models. In 1999, a contract for 25,000 knives was split between LanCay and Ontario (12,500 each).
Ontario Knife Company also participated in later contracts, and is one of the current (as of 2005) contractors for producing them. These can be identified by the blades, which are marked "M-9 / ONTARIO / KNIFE CO / USA".
In 2012, Tri-Technologies was awarded a contract for 40,000 M9s marked "M9/06MA8/USA". 
The M7 bayonet, introduced in 1964, was used as a bayonet on the M16 rifle and as a fighting knife. The M9 multipurpose bayonet system is used as a bayonet on the M16 series rifle, on the M4 series carbine, as a fighting knife, as a general field and utility knife, as a wire cutter when used on the sheath, and as a saw. The M9 also fits the Mossberg 590 Special Purpose shotgun.
|Entered Army Service:||1965||1987|
|Blade length:||6.5 in||7 in|
|Total length:||11.75 in||12 in|
An overview of M9 types made by Buck Knives, one of the manufacturers of M9 bayonets. The 5,000 for the U.S. Marines are included under the U.S. Army numbers in this listing.
|Field Knife (Japan I)||0188-J1-0||1,956|
|Field Knife (Japan II)||0188-J2-0||504|
A bayonet is a knife, dagger, sword, or spike-shaped weapon designed to fit on the end of the muzzle of a rifle, musket or similar firearm, allowing it to be used as a spear-like weapon. From the 17th century to World War I, it was a weapon for infantry attacks. Today it is considered an ancillary weapon or a weapon of last resort, although it is still used for ceremonial purposes.
Victorinox is a knife manufacturer and watchmaker based in the town of Ibach, in the Canton of Schwyz, Switzerland. It is well known for its Swiss Army knives. The Swiss Army knives made by Victorinox are made of a proprietary blend hardened steel from Germany and France. Since its acquisition of rival Wenger in 2005, it has become the sole supplier of multi-purpose knives to the Swiss army. It is the biggest manufacturer of pocket knives in the world; in addition, the company licenses its logo for watches, apparel, and travel gear.
The Camillus Cutlery Company was one of the oldest knife manufacturers in the United States as its roots date back to 1876. The Company produced millions of knives until it filed for bankruptcy in 2007. Its brand name and intellectual property rights were purchased by Acme United Corporation, which re-launched the Camillus brand in May 2009 using modern materials.
Buck Knives is an American knife manufacturer founded in Mountain Home, Idaho and now located in Post Falls, Idaho. The company has a long history through five generations of the Buck family from 1902 to the present day. Buck Knives primarily manufactures sport and field knives and is credited with inventing the "folding hunting knife" and popularizing it to such a degree that the term "buck knife" has become synonymous with folding lockback knives, including those made by other manufacturers.
A trench knife is a combat knife designed to kill or incapacitate an enemy at close quarters, such as in a trench or other confined area. It was developed as a close combat weapon for soldiers attacking enemy trenches during the First World War. An example of a World War I trench knife is the German Army's Nahkampfmesser.
Strider Knives, Inc. is a custom and production knifemaking facility headed by Mick Strider based in San Marcos, California.
Survival knives are knives intended for survival purposes in a wilderness environment, often in an emergency when the user has lost most of their main equipment. Most military aviation units issue some kind of survival knife to their pilots in case their aircraft are shot down behind enemy lines and the crew needs tools to facilitate their survival, escape, and rescue. Survival knives can be used for trapping, skinning, wood cutting, wood carving, and other uses. Hunters, hikers, and outdoor sport enthusiasts use survival knives. Some survival knives are heavy-bladed and thick. Other survival knives are lightweight or fold in order to save weight and bulk as part of a larger survival kit. Their functions often include serving as a hunting knife. Features, such as hollow handles, that could be used as storage space for matches or similar small items, began gaining popularity in the 1980s. Custom or semi-custom makers such as Americans Jimmy Lile, Bo Randall, and Chris Reeve are often credited with inventing those features.
The OKC-3S is a bayonet developed by the United States Marine Corps to replace the M7 bayonet and M9 bayonet as its service bayonet for the M16 family of rifles and M4 series carbine. This multipurpose bayonet provides greater durability than the M7 and also functions as a fighting knife.
A combat knife is a fighting knife designed solely for military use and primarily intended for hand-to-hand or close combat fighting.
The Gerber Mark II is a fighting knife manufactured by Gerber Legendary Blades from 1966 to 2000, with an additional limited run of 1500 in 2002, and full production resuming as of July 2008. It was designed by retired United States Army Captain, Clarence A. “Bud” Holzmann, who based the pattern on a Roman Mainz Gladius.
Ontario Knife Company, also known as OKC, is an American manufacturer of knives and other edged and military tools.
The M7 bayonet is a bayonet that was used by the U.S. military for the M16 rifle, it can also be used with the M4 carbine as well as many other assault rifles, carbines and combat shotguns. It can be used as a fighting knife and utility tool. It was introduced in 1964, when the M16 rifle entered service during the Vietnam War.
The Aircrew Survival Egress Knife or ASEK is a U.S. Army aircrew survival knife, designed and initially manufactured by the Ontario Knife Company, and entered service in 2003.
The Mark I trench knife is an American trench knife designed by officers of the American Expeditionary Force (AEF) for use in World War I. It has a 6.75 in (17.1 cm) double-edged dagger blade useful for both thrusting and slashing strokes, unlike previous U.S. trench knives such as the M1917 and M1918. The handle is made of cast bronze and uses a conical steel nut to hold the blade in place. The Mark I's blade was blued with a black oxide finish, the bronze handle was chemically blackened, with cast spikes on the bow of each knuckle. The spikes were intended to prevent an opponent from grabbing the knife hand, as well as to provide a more concentrated striking surface when employed in hand-to-hand combat.
The M3 trench knife or M3 fighting knife was an American military combat knife first issued in March 1943. The M3 was originally designated for issue to soldiers not otherwise equipped with a bayonet. However, it was particularly designed for use by forces in need of a close combat knife, such as Airborne Units and Army Rangers, so these units received priority for the M3 at the start of production. As more M3 knives became available in 1943 and 1944, the knife was issued to other soldiers such as Army Air Corps crewmen and soldiers not otherwise equipped with a bayonet, including soldiers issued the M1 carbine or a submachine gun such as the M3 "grease gun".
Ka-Bar is the contemporary popular name for the combat knife first adopted by the United States Marine Corps in November 1942 as the 1219C2 combat knife, and subsequently adopted by the United States Navy as the U.S. Navy utility knife, Mark 2. Ka-Bar is the name of a related knife manufacturing company, Ka-Bar Knives., Inc., of Olean, New York, a subsidiary of the Cutco Corporation.
The Glock knife is a military field knife product line designed and produced by Glock Ges.m.b.H., located in Deutsch-Wagram, Austria. It can also be used as a bayonet, by engaging a socket in the pommel into a bayonet adapter that can be fitted to the Steyr AUG rifle.
A fighting knife has a blade designed to most effectively inflict injury in close-quarters physical confrontations. The combat knife and the trench knife are examples of military fighting knives.
The French Nail were locally fabricated and converted bayonets, knives and stabbing weapons for use in the First World War. These were crude stabbing spikes made by adding a point to a steel stake which had its rearmost section heated and bent into a crude handle.
The design submitted by the firm of Phrobis III of Oceanside, California, won the competition. It was a hands-down win with Phrobis having a zero failure rate while the worst design had a failure rate of 74% (Armed Forces Journal).