[Xan Stepp]

Does anyone know the etymology of the term blood grooves? I was thinking about it the other day, and while I have no doubt that the primary purpose of fullers would be to lighten and strengthen the blade, I have to imagine that they also channeled blood down the center of the blade. I realized that it was entirely possible that fullers may have been called blood grooves by contemporaries after an observed effect rather than primary purpose. However, it is also equally possible that they were given the term at a later date when the function of the fuller was simply assumed by people with little practical experience.

So my question is whether anyone does know for sure, and can document the origin of the term? I've don't remember ever having seen it in medieval or renaissance sources, but then again I don't remember the term fuller either.

[Craig Johnson]

The term "Blood Grove" in the context of a description for a fuller I believe is a modern alliteration. I have not found any period use of the term or reference to this particular function being described. In discussions with surgeons and emergency room doctors the whole concept is pretty much a wash. There is no technical need or function for such a grove in a devise puncturing the body. As one said to me "Humans are soft, steel is hard."

Their is no suction component to wounds and the trauma created by a piece of steel entering the human body that needs much help in increasing the results of said intrusion.

Now if we could find such a comment from a period source it would be quite interesting, but I have not come across it in many years of watching for it.

Best
Craig

[Bill Tsafa]

I don't know know accurate it was, but I saw a documentary at least 10-15 years ago to said that "blood groves" for the purpose of "relieving the suction on the blade" were first used on bayonets in the late 19th or early 20th century. I don't remember what people they were talking about, I suspect some eastern European group. From there, the use of blood grooves spread to most bayonet knives. Again this was a documentary form 10-15 years ago, so the info may be out of date. I am hoping someone else has more information on this. This documentary was the first time I heard the term "blood groove".

I have seen the blood grooves on WWI and WWII bayonets. It is a very thin line, not wide like a fuller. My ka-bar has a slightly wider one, but short. Clearly the purpose of it is not to reduce the weight like a fuller on a sword. Regardless if the bloodgrove is effective or not in breaking suction, for most of the 20th century people believed it did and put blood groves on the blades for that reason. Hence, those ARE blood grooves on bayonet knives, not fullers, based on the reason why they were put on there.

[Jason Manville]

If you Google the term “blood grove”, you are often re-directed to sites regarding “fuller” In most of my discussion, I have heard “blood groves” used when referring to a knife or shorter blade. I have heard the term “fuller” used when referring to a sword or longer blade.

The term “blood grove may be nothing more than a marketing term intended to make a knife seem better or more effective.

If we want to discuss the purpose of a fuller on a sword blade:

The main function of a fuller is to stiffen and lighten a sword blade.

1.) When slashing the main tension of the cut is along the back of the blade. By removing material; sword makers can lighten a blade without weakling it.

2.) In an unfullered blade, there is only the single spine. Once you add a fuller you actually produce two spines along the blade

There is no evidence to support the “blood letting” myth regarding fullers. No evidence that there is any suction when stabbing or cutting a person/animal. If you can cut your way in, you can cut your way out.

On shorter blades the fuller does add a nice decorative aspect. I personally like the look of a fuller on most blades. However, if the blade is under 24”, I doubt that a fuller would add much in the way of functionality.

[Bill Grandy]

[Bill Tsafa]

Clearly I was questioning the accuracy of the documentary myself.

What is not questionable is that many WWI and WWII knives have blood grooves (or fullers) on them. The question then becomes:

1-Is it there to make the blade lighter? If yes, its a fuller.
2- Is it there to break suction? If yes, its a bloodgrove.
3- Is it there to be decorative? What would Gen. Patten say?
4-What did the men who used those weapons call them? I suspect blood grooves.


A fuller on knife is barely going to take off an once in weight. Its not worth the trouble. Testing may prove that a blood groove does nothing to help in breaking suction. That does not change the fact that they were used on bayonets because they believed it did at the time.

[Craig Johnson]

I think you have hit on it Bill. Sometimes you will get something from popular culture that sneaks into supposed academic discussion as it gets assumed to be true rather than any first hand knowledge or even a simple check with someone who has first hand knowledge.

I think blood grove will have to join the list of great sword myths that I have heard from people who should know better.

List of sword Myths

1) 30 pound sword
2) Swords can slash through armor and my favorite off shoot -(Japanese swords can cut through teh barrel of a machine gun)
3) Scottish Highlanders threw their Claymores with deadly affect
4) Real swords don't flex.
5) Swords need to be razor sharp
6) Blood Groves - function and name i.e.(related sucking action of would trapping blade)

This might make a good thread on its own "What are the worst sword myths?"

Best
Craig

[Craig Johnson]

[Eric Myers]

Hi Craig,

Do fullers actually increase the stiffness of a blade, or just lighten the blade without sacrificing much stiffness? I have a hard time believing that the sides of a fuller act as additional spines, but perhaps that is just how I am looking at it. If I take two flat bars and put fullers in one, it shouldn't be any stiffer than the other.

[Bill Tsafa]

I don't suspect a fuller does not work any differently then an I-beam. The I-beam is not stronger then if you had a solid bar of steel in the same dimensions. The solid bar is stronger but weighs at least 10 times as much (vs I-beam) and is much more expensive. The I-beam is however a more efficient use of three thinner sheets of mettle that greatly improves their strength. The same concept applies to a rubber hollow ball vs a solid one of the same material.

The wording I would use to describe a fuller is... the removal weight from a blade in such a way that it does not significantly weaken the blade or change its dimensions. .

[Eric Myers]

[Bill Tsafa]

[J.D. Crawford]

[Mark Millman]

Dear Mr. Tsafatinos,

[Xan Stepp]

First of all, I don't buy the concept of "suction" in a wound; the physics just doesn't make sense. First of all, suction is usually caused by a differential between atmospheric pressure and a closed volume. I don't think that most swords would adequately seal a wound so that there would be no air exchange between the systems. However, even if they did the pressure differential would be along the cross-section of the blade, and at 14 psi at one atm, the cross section of the sword is too small to add more than about 10 lbs. to the force required to remove the blade, and if the wielder can't muster that, he has bigger problems. Beyond that, the blood in the human body is under a considerable amount of pressure, and would be trying to force the blade out rather than keep it in. That's how I see the physics, but does anyone have another opinion?

Also, look at historical blades. Consider a Roman infantry sword (no fuller) and a Viking Age sword (with a fuller), which is more likely to be used to inflict a stabbing wound? Also, if it really were an issue of suction, wouldn't we expect to see fullers on spears in the Viking Age?

As for the "blood grooves" in historical bayonets. Even though the amount of weight saved is minimal, remember that they were place on the end of what could be very long guns, multiplying their effective weight for the wielder. So that one ounce saved, may feel like more to the soldier.

However, it is also possible that "blood grooves" were included in these bayonets because the manufacturers had bought into the myth that the blade could get stuck, and were merely perpetuating false information.

But my original question still remains, can anyone track either the term "blood groove" or fuller. When did these words begin to appear?

[Mark Millman]

Dear Mr. Myers,

[Mark Millman]

Dear Mr. Stepp,

[Xan Stepp]

Mr. Millman,
You're absolutely right, I don't know why the idea to check the OED never occurred to me. It's an obvious solution that escaped me for some reason. I'll check it as soon as things get up and running over here after the holidays unless someone posts it here first.

[Eric Myers]

[Gavin Kisebach]

Every time I have read an account of a weapon getting stuck, it has been bone related, not suction related. For some reason the only example that comes specifically to mind is the fictional reference from All Quiet on the Western Front, where the soldiers use sharpened shoves to fight rather than bayonets, which tend to stick in ribs.

This makes far more sense to me prima facie than a weapon sticking in flesh. A modern example that cemets this notion is the footage of a person at a track and field event who gets hit in the shouldet with a javelin, and reflexively pulles the javelin out immediately without any apparent difficulty.

The other issue that I take with the suction theory is that fullers appeared on swords that were not at all designed to thrust, like the kophesh, and notably absent on some very thrust oriented swords that in fact have a diamond cross section.