WWII U.S. Army M3 Trench Knife / M4 Bayonet


November 6, 2012, 12:13 PM
While the Marines had the Ka-Bar & USN MKII early in 1943, the Army was left with a limited number of 1917 / 1918 trench knives still in storage from WWI.

They were considering the same Combat/Utility knife the Marines adopted, but they apparently determined in the numbers they envisioned needing during the course of the war, thousands of pounds of high grade steel could be saved by adopting the narrower blade used on the M3.
The design was adopted Jan 14, 1943.

They have a 6 9/16" blade, with a steel guard bent on the top for blade edge orientation in the dark.

IMO: Although successful as a fighting knife, it was not nearly as good as the Navy MKII / Ka-Bar for the other 99.9% of the time it was needed for all the other things a solder uses a good knife for.

During the course of the war, at least 9 companies made M3’s.
They were made by Pal, Utica, Camillus, Imperial, Kinfolks, Case, Aerial, Robeson, and Boker.
Total production totaled 2,590,247 according to some sources.

The first knives were deeply blade stamped with M3 - Makers name - 1943 on the right side.
Later, the 1943 was dropped, and more makers info added.
Still later, all markings were moved to the guard, as it was found the deep blade stampings weakened the blade.

They were first issued in the M6 leather sheath.
It was a 15 7/8" long, drop-leg design intended to carry the knife well below the parachute harness and other equipment the solder was burdened with.
It was soon found to be ungainly and unsatisfactory, and was replaced with the M8 hard scabbard with belt loop.
The M8 was soon replaced with the M8A1 hard scabbard which was the same as the M8, but also had a wire pistol belt hook added.

Shown here are a blade marked Imperial, and a blade marked Utica, and a guard marked Imperial M4 Carbine bayonet in U.S. M8 hard fiber sheaths.

In May of 1944 a bayonet was adopted for the M1 Carbine, and the M3 Trench knife became it.

The M4 bayonet is basically a M3 Trench Knife with bayonet attachment handle for the M1 Carbine.
Some early transition M4 bayonets will be found with M3 stamped blades.




A post-war Kutmaster (Utica) made from surplus M3/M4 blades after the war and sold commercially in hardware stores and sporting magazine ads for like, $1.98.
A older gentleman in the neighborhood gave me this one when I was about 9 years old.


I regret not buying every 1943 blade marked M3 I could find years ago when they were selling for next to nothing. After "Saving Private Ryan" and "Band of Brothers" came out, prices went off the charts!
Now that the buzz from all that has died down, prices have fallen again somewhat.

But still today, excellent condition blade marked M3's can bring several hundred dollars depending on the maker & rarity.


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November 6, 2012, 01:23 PM
It's interesting how far back the hard scabbards were used. When did the M-8 actually come onto the scene? I guess I always assumed they were a product of the cold war. Duh!! I guess the WW2 M-1 bayonet scabbard must have been hard too. I just never thought about it.

November 6, 2012, 01:59 PM
The first plastic (cellulose acetate butyrate) hard scabbards of the type I know of was the M3 issued with the M-1942 16" Bayonet for the 1903 Springfield and M1 Garand.

There was a M-1917 hard sheath for the M-1917 17" bayonet used on the 1917 Enfield and all the trench shotguns in WWII.

Sheath models progressed to the M7 sheath for the 10" bayonet, M8 & M8A1 for the M3 Trench knife and M4 Bayonet.

Later M5 M1 Garand, M6 M-14, and M7 M-16 bayonets continued to use the M8A1 hard sheath developed in WWII.

I don't know what the M1, M2, M4, & M5 model numbers were used for, but as far as I know, none of them were ever adopted for general issue.

In the mean time, the Navy had the USN MKII and MKI Grey hard sheaths from WWII on.

Patent application # 312,192 was filed by Edwin L. Beckwith and Charles P. MacIver on January 3, 1940.
Military tests were conducted starting in October 1940.
The design was accepted August 1941.
And the first production was undertaken by the Beckwith Manufacturing Company of Dover, New Hampshire for the initial order of 1,000,000 M3 scabbards.
Production started October 1941.
It was completed in October 1942.

Talk about the getting on the "Fast Track" manufacturing bandwagon!!


November 6, 2012, 03:12 PM
I was going to say, that blade looks just like the one on my M7 bayonet, and I know it has an M8A1 sheath, too.

November 6, 2012, 03:34 PM
M5 was an M1 Garand bayonet using the M3/M4 blade.
Here is a pic of my CMP M1 Carbine with it's Norwegian M4 copy (also from CMP). The M8 sheath was my fathers from WWII.

November 6, 2012, 03:41 PM
Of course it was!! :banghead:

Thanks for reminding me of that!!


November 6, 2012, 05:52 PM
The blade is just the same for the bayonet and the fighting knife and the reason for the that probably had little to do with saving money and everything with ease of manufacture since the same components save the guard and butt would be used to produce the fighting knife.

November 6, 2012, 07:50 PM
had little to do with saving money I never said it did have anything to do with bayonet costs.
Especially when you factor in the fact the M3 Trench Knife design proceeded any of the later bayonets using the same blade design by at least 2-3 years.

I have read in more then one account that part of the decision to go with the M3 in early WWII was based on cost & steel savings over the Navy MK-II / Ka-Bar design, x several million knives the Army thought they would need to produce during the course of the war.


November 7, 2012, 05:58 AM
I really like the M3 style blade. Dr. "Elephant" (that is how a three year old me pronounced his name and it stuck) gave me an M5A1 on a fishing trip with my grandfather PaPa when I was about 7. It was in the metal tipped sheath. I soon obtained a pistol pelt with the correct holes for it and it became a near constant companion in woods walks.WHen I got involved in JROTC in highscholl this blade went on the end of my issue M-1 Garand to make bayonet training more fun than leaping about with a naked rifle....and caused a veritable arms race among others and so M5s M5A1s and various older M-1 bayonets showed up. Imagine a kid showing up at school today and tossing a cut down M1942 in his wall locker to have for when he could mount it on his fully functional M-1 Garand in the after noon. 20 years ago it was stolen from one of those storage rental places while I was bouncing about. (they also got an AK 47 bayonet just before they became fairly common that had gotten many oos and ahs at gun shows and the sheath for my Belgain made pre wwII US navy machette)

While working for the state 4H HQ I got to handle some of the artifacts from the spanish Attocia shipwreck that were sold at auction to raise money for the organization. AMong the stuff and most pleasing to me was a blade sinister that had lost all other parts. Now iron and steel does not normally fair well in the gulf of mexico, but this blade was still solid and except that it was about16 inches long and scaled as widely it was the spitting image poportionally of the M3.

I was fortunate enough to have a "good" M7 issued to me when I was an EM though some of the nasty lowest bidder blades were in my unit. As I was my platoon's assitant to the Company armorer I quietly moved bayonets around (only the sheaths were numbered) until all our bayonest were good solid types with none of those weird stripes and jagged edges. I also sharpend every one and caused a fuss when I sharpened the "false edge" until I showed them that that was proper according to the specs on the bayonets. No good dead gong un punished I had keeping the platoons old wood handled e-tools sharp added to my duties after that.


November 7, 2012, 11:45 AM
Good story kBob!

BTW: I'm a little surprised nobody commented on what the M3's were laying on in the first photo!

Yep! Besides the 1911A1 in a WWII holster & belt.
Thats a M1A1 Carbine in an original WWII canvas jump case under the knives!


November 7, 2012, 03:42 PM

Knife forum notwithstanding (excellent collection you've been displaying over the past few days and with excellent information accompanying it), don't be shy about showing that M1A1!

November 7, 2012, 06:46 PM
I've seen a photo or two of WWII soldiers carrying their fighting knife tucked between their web belt and their holstered .45 pistol.

November 10, 2012, 02:10 PM
Great Knife History!

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