# M9 bayonet

The M9 bayonet, officially known as the M9 Phrobis III, is an American multi-purpose knife and bayonet officially adopted in 1986 by the United States Armed Forces for the M16 rifle. Featuring a 7-inch (18 cm) blade and issued with a sheath designed to double as a wire cutter, the M9 bayonet is designed to function not only as a combat knife but also as a multi-tool, capable of serving as a wire cutter, metal slicer, bottle opener, and screwdriver.

## History

In 1973, the U.S. military retired the M7 bayonet, introduced in 1964, due to changing military tactics and increasing reliance on high technology that made the use of bayonets in combat unlikely and largely unnecessary. However, this left them without a cutting tool.
The M9 bayonet was designed and developed by Charles A. "Mickey" Finn at his R&D company, Qual-A-Tec. Finn sought to develop "a sort of Swiss Army knife for field use", out of an actual proper knife that could also be used for military combat purposes. Qual-A-Tec's M9 bayonet design won over 49 other competitors, and was the only contract bid entry to have a zero percent failure rate. It is an improved, refined copy of the 6H3 bayonet developed by the Soviet Union for the AKM.
Finn later produced the M9 under the Phrobis III name, filling a military contract for 325,000 units. Buck Knives was contracted to produce 300,000 units, and sold a commercial version under their own name until 1997. 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, but unlicensed copies from Asia and Mexico cut into his legitimate sales.
After the Phrobis III bayonet contract was completed in 1989, rights to the M9 reverted to the United States Army and there were many subsequent versions from other companies. It is issued by the U.S. military 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. Although it has been claimed that the M9 may be more prone to breakage than the older M7 bayonet, the M9 has a 20% thicker blade, the tang is reduced from (0.235 to 0.195 in (0.60 to 0.50 cm)) in thickness, and a 75% greater cross-sectional area of steel in the blade than the M7.

## Variants

The M11 knife, also known as the 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. It is not strictly a bayonet, as it has no mounting catch or muzzle ring; rather, it is more of a revision to the Buckmaster 184/188 knife, which was the basis for the Phrobis XM-9 prototype bayonet.

## Makes

There have been five main makes of M9s: Phrobis III, Buck Knives, LanCay, Ontario, and Tri-Technologies.
Starting in 1987, Phrobis subcontracted Buck for production in its initial U.S. Army contract, finishing in 1989. It was around this time that Buck sold commercial M9s as well, lasting until 1997. LanCay received its first contract in March 1992, taking over production from Buck, for 30,000 knives, later increased to 50,000, 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, with each company producing 12,500 knives each. Ontario also participated in later contracts, and continued to produce them well past 2005. In 2012, Tri-Technologies was awarded a contract for 40,000 M9s.

## Comparison

The M7 bayonet, introduced in 1964, was used as a bayonet on the M16 rifle, M4 carbine, 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 M7 and M9 bayonet can also be mounted onto the Mossberg 590A1 shotgun.
| Designation | M7 | M9 |
| Entered Army Service: | 1964 | 1986 |
| Blade length: | 6.75 in (17.1 cm) | 7 in (18 cm) |
| Total length: | 11.75 in (29.8 cm) | 12 in (30 cm) |

## Production numbers

These are production numbers for M9 bayonets produced by Buck Knives. The 5,000 bayonets produced for the United States Marine Corps are included under the U.S. Army numbers in this listing.
| Type | Buck Part# | Quantity |
| U.S. Army | 0188-00-0 | 330,254 |
| Australian | 0188-A1-0 | 20,050 |
| Abu Dhabi | 0188-AD-0 | 1,500 |
| Commercial (black) | 0188-BK-0 | 14,213 |
| Diemaco | 0188-DM-0 | 8,681 |
| Marine Prototype | 0188-MC-0 | 350 |
| Commercial (green) | 0188-CB-0 | 28,238 |
| Field Knife (Japan I) | 0188-J1-0 | 1,956 |
| Field Knife (Japan II) | 0188-J2-0 | 504 |
| Total: | Total: | 405,746 |

## Users

* Abu Dhabi: Security forces
* Australia: Australian Defence Force
* Chile: Lautaro Special Operations Brigade
* Hong Kong: Special Duties Unit
* The Netherlands: Armed forces of the Netherlands
* New Zealand: New Zealand Defence Force
* Singapore: Singapore Armed Forces
* Thailand: Royal Thai Armed Forces
* USA: United States Armed Forces (other than the Marine Corps which uses the OKC-3S bayonet)
* India: Indian Army