The USM3 Fighting Knife Guide

You will find here an article about the USM3 Fighting Knife. An inseparable element of the silhouette of the U.S. soldier of World War II, the USM3 Trench Knife was originally created to arm elite troops (paratroopers, rangers, ...). In the field, it was actually distributed to fighting troops without bayonets.

History of the USM3 knife

The first needs of the United States in combat knives appeared during the 1st World War. To remedy this problem the US Army had the Trench Knifes Mle1917, Mle1918 and Mle1918 mk1 manufactured. At the end of the First World War, the M1917 and M1918 were decommissioned. The M1918 mk1 is kept and distributed while stocks last.
When the USA entered the war in 1941, the combatants quickly felt the need to have a combat knife at their disposal. In order to meet this need, the M1918 knife stock was distributed while waiting to design the ideal knife. It arrived in 1943 as the 'US M3 Trench Knife'.
Its manufacture although ephemeral began in March 1943 to finish in July 1944. The total quantity of M3 manufactured in this short period of time was about 2,590,240 pieces. The M3 was later replaced by the M4 bayonet for the US M1 rifle. Its history did not stop there since it was distributed until stocks were exhausted. Soldiers of the French army also benefited from it for many years, since the M3 took part in the fighting in Korea, Indochina and Algeria.

USM3 fighting knife WW2
A nice example of USM3 fighting knife


Description of the USM3 fighting knife

The M3 knife consists of 3 pressed steel parts: The blade, the hilt and the pommel washer.

Its total length is 292mm (11 5/8 inches). Its blade is double-edged and has a length of 170mm (6 11/16 inches). Its width is 21.8mm (21.8mm) and thickness is 4.5mm (4.5mm).

The guard is double quillons, one of which is bent forward to allow thumb rest, its length is 57.7mm, its width is 13.3mm for a thickness of 3mm.

The pommel is 6mm thick. It is fixed to the blade by crushing the tang on most models. We find some manufactures where the pommel is pinned with two through nails.

Its 120m long handle is made of a stack of leather washers. Some of these washers have a smaller diameter in order to form grooves to facilitate gripping. The washers are delimited by the guard on one side and the pommel washer on the other. On some models the end washers are made of plastic instead of leather.

The total weight is about 230g.

The M3 was originally distributed with the M6 leather sheath (M6 Scabbard) reinforced with metal additions to reinforce it. Very fragile in spite of its reinforcements, it was quickly replaced by the M8 fiber sheath (M8 Scabbard), then finally by the M8A1 sheath (M8A1 Scabbard).

The manufacturers of the M6 scabbard: Boarwood, Milsco, Moose, Sbl co, Viner Bros.

Details on the USM3 knife handel

The handle is made of a stack of leather washers. Although the regulation number of grooves is 8, it is not uncommon to see models with 5, 6 or 7 grooves. We can also see models with a brown plastic washer on the guard and a black plastic washer on the pommel. The pommel washer can be either pinned with silk or set.

USM3 pommel details
USM3 pommel versions


Manufacturers of the M3 knife

The U.S. M3 knife was manufactured by 9 different companies:

Aerial (Aerial Cutlery ) --> 51,748 pieces,
Boker (H. Boker & co.) --> 31,300 pieces,
Camillus (Camillus Cutlery co.) --> 404,109 pieces,
Case (W.R. Case & sounds) --> 300,465 pieces,
Imperial (Imperial Knife co.) --> 854 015 pieces,
Kinfolks (Kinfolks inc.) --> 135,548 pieces,
Pal (Pal Blade & Tool co.) --> 121,231 pieces,
Robeson (Robeson Cutlery co.) --> 36 575 pieces,
Utica (Utica Cutlery co.) --> 655,230 pieces.

Most common manufacturers are CAMILLUS, IMPERIAL, PAL, UTICA

USM3 knife markings

There are 5 types of USM3 markings.

1st Type marking (1943) :
On the blade -> Manufacturer's name + Type + Year of manufacture ex: PAL USM3 1943
USM3 marking type 1


2nd Type marking (End of 1943) :
On the blade -> Manufacturer's name + Type ex : PAL USM3
M3 Marking 2nd type


3rd Type marking (1944) :
Guard marked -> Manufacturer's name + Type ex: PAL USM3
US M3 knife marking


4th Type marking :
On the blade and guard -> Manufacturer's name + Type ex : PAL USM3

5th Type marking :
No marking on the blade and the guard -> ...

The most common markings are the first 3. The 4th is actually the result of the assembly of blades of the 2nd type and guards of the 3rd type. Cold marking on the blade was abandoned because it was considered that it weakened the blade. Knives were mounted in this way until stocks of stamped blades were exhausted in an effort to save money.
The 5th type is in fact due to manufacturing errors (forgetting to stamp the blades or guards), but the knives were still accepted by the US Army Material Department (Ordnance corp).
In any case, for these 5 types of markings, the pommel plate (end cap/butt cap/pommel) must be struck with the flaming bomb (flaming bomb / ordnance bomb), the symbol of the Ordnance corp.

USM3 scabbard types

M6 scabbards :

Characteristics :

Made of leather reinforced with metal parts (plates + clips). This type of scabbard was manufactured only during the year 1943.

Markings :

US M6 + Manufacturer's name + 1943 + Ordnance corps

Manufacturers :

Milsco (Milwaukee Saddlery) at 140,494 copies, L&C (Lyon & Coulson) at 40,000 copies, Sbl co (Service Boots & Leggins) at 35,200 copies, Barwood (L.J. Barwood) at 29,000 copies, Moose co. (Moose River Shoe.) 28,000 copies and Viner Bros. 28,000 copies.


M8 and M8A1 scabbards :

Characteristics :

M8 (1st Model): Made of fiber, metal and spun cotton canvas.
M8 (2nd Model): Same as 1st Model but with the addition of a hook to attach the sheath to the M1936 belt.
M8 A1 : Same as M8 (2nd Model) but with the spun cotton part a little longer.

Markings :

U.S. M8 + Manufacturer's name
U.S. M8 A1 + Manufacturer's Name

Manufacturers :

BM Co.

USM3 scabbard types


Important note : As the fiber sheaths are quite fragile (we see them quite often with the broken end), the M8 A1 was modified after the war. A metal tip was added.

If you collect USM3 fighting knife, have a look at our knife selection, you will find several authentic USM3 available. We select the most interesting fighting knives that we find online from serious collectors and militaria suppliers.