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Question by 99explorer. Uploaded on April 05, 2011
Make it easier to pull out.
What war was the groove developed?
The "blood groove"is actually called a fuller and its intent is to give the blade strength while reducing the weight somewhat. No one knows exactly when it was developed, but it was a long,long time ago, like well before the Vikings were ravaging England and Northern Ireland and is quite a technological achievement.Its advantage is evident in the use of swords. There is some debate on whether or not it has value on a hunting knife. I have read arguements on both sides whether or not it actually aids in knife removal.
Have read enough WWII books to know the groove made it easier for U.S. Marines to pull the knife out of Japs.
Looking at old bayonets you can see the development of the blood groove throughout the years.
Does the samurai sword have a blood groove?
Here is an expaination from A.G Russell's website:
What is a Blood Groove For?
This question comes up every 8 months or so. The blood groove on a knife probably is derived from the channel present on swords, where it is called a "fuller". There are some persistent myths floating around about the function of blood grooves, from "releases the vacuum when the knife is thrust into a person" to "no functional use, purely decorative". Let's talk about these wrong answers first, before we talk about the right answers.
Wrong Answer #1: Releasing the Body Suction
Basically, this theory postulates that the blood groove is present to facilitate withdrawing the knife from a person/animal. In this scenario, it is said that the animal's muscles contract around the knife blade, and that this causes a vacuum, which makes the knife difficult to withdraw. But on a knife with a blood groove, blood runs through the blood groove and breaks the suction, so the knife can be withdrawn with less difficulty.
One problem is that there's no evidence that this suction ever really happens. Also, over and over again people report that there is no difference whatsoever in the difficulty of withdrawing a knife with a blood groove vs. one without. This is one theory that has been tested and found wanting.
Yes, I realize you may have heard this myth from your deadly knife instructor, or read it in a book somewhere. But the experts agree that it is false. If your knife can cut its way in, it can just as easily cut its way out, with or without a blood groove.
And with that, I am going to change terminology from "blood groove" to "fuller", since we all now know the so-called "blood groove" is not playing a blood-channeling function.
Wrong Answer #2: Purely Decorative
There is a grain of truth to this one. Although a fuller does play a functional role, on a short knife the effect might be so small as to be insignificant. Many believe the fuller plays a strictly decorative role on knives or swords under 2 feet long. As the knife or sword gets bigger, the fuller plays an increasingly important role. On smaller knives, it is indeed probably just decorative.
Okay, so what substantive role does the blood groove/fuller play? The bottom line is, it does two things:
1. It stiffens the blade 2. It lightens the blade
That first statment has been the subject of some controversy, with some people sending me equations purporting to show that the removal of material cannot make the blade stiffer. I will table for now the question of "does the blade get stiffer, in some absolute sense, due to the fuller?" Rather, I'll weaken the claim to say that the blade *feels* stiffer to the user who is waving it around -- because it's stiffer for its weight.
I'll reproduce a post by Jim Hrisoulas which lays things out clearly (re-printed with permission):
When you fuller a blade you do several things:
1: You lighten it by using less material, as the act of forging in the fuller actually widens the blade, so you use less material than you would if you forged an unfullered blade. (In stock removal the blade would also be lighter, as you would be removing the material instead of leaving it there).
2: You stiffen the blade. In an unfullered blade, you only have a "single" center spine. This is especially true in terms of the flattened diamond cross section common to most unfullered double- edged blades. This cross section would be rather "whippy" on a blade that is close to three feet long. Fullering produces two "spines" on the blade, one on each side of the fuller where the edge bevels come in contact with the fuller. This stiffens the blade, and the difference between a non-fullered blade and a fullered one is quite remarkable.
Fullers on knives do the same thing, although on a smaller blade the effects are not as easily seen or felt. Actually looking at fullers from an engineering point of view they really are a sophisticated forging technique, and it was the fullered swordblade that pointed the way to modern "I" beam construction.
When combined with proper distal tapers, proper heat treating and tempering, a fullered blade will, without a doubt, be anywhere from 20% to 35% lighter than a non-fullered blade without any sacrifice of strength or blade integrity.
Fullers were not "blood grooves" or there to "break the suction" or for some other grisly purpose. They served a very important structural function. That's all. I have spent the last 27 years studying this and I can prove it beyond any doubt...
Source: rec.knives Newsgroup May 1998
NM Impressive and a common sense answer. plus 1
It depends on the lenght of the blade. If it s a short knife it is pure asthetics.
If it is a log blade the fuller can be applied to physics, strengh, and the release of suction when puncturing flesh. That being said there is no groove on the american bayonet...
The fuller or Blood groove was to Punctur flesh and release body gases apound removel of the blade.
buckhunter; I have never seen a katana with a fuller. Different manufacturing technics maybe?
Carl, thank you.
I googled it. The "fuller" on bayonets were for strength, not ease of pulling out. I had always thought the groves in bayonets were for blood letting. Maybe I should rephrase this. I have read in several books of problems pulling bayonets or knives out.
I pulled my M3 and Marine Corp Ka-bar out of the safe. The M3 does not have a blood groove but the Ka-bar does. I would still like to know where the term blood groove came from if not for it's named goal.
By the way, the M3 is a very nasty knife.
I am not posting this as an argument, just what I heard, that on fighting knives at least, the fuller would allow whatever stabbed to 'bleed out' quicker.
Although this doesn't seem likely for a combat knife, as you would have to stand there too long.
The only modern adaptation I saw was at a store in Georgia, which was an arrow with a 'blood channel' in it. The advert said it was to bleed the deer out faster, and make a better trail for tracking. I don't think it ever caught on generally.
NM is on target with this one, great answer!
This is an interesting topic. Possibly of myth-buster type.
I am going guess two thing:
The difficulty of pulling a knife or bayonet out which I have read about in several literary works as difficult at times is either an exaggeration or fictional
Am I mistaking the serrated edge as the culprit and not suction? I beleive the original Marine Corp knife had a serrated edge?
The command fix bayonets, I believe was last used in Korea. The main purpose of the bayonet was to issue every soldier a knife. Which was far more multipurpose than a bayonet. As far as the Samurai sword. I believe it was used as a slashing weapon. It's strength and rigidity was derived from the curve achieved in it's tempering.
It may have some history, but the purpose was, I think, always questionable. Today, it's decorative.
No serrated edge on the Ka-bar.
This link points to the actual schematic of the 1942 Ka-bar. In that, it is called a blood groove also.
NM was right on. The fuller is all about keeping the blade light and strong, and has nothing to do with blood letting. My katana has a fuller, and it is a real one not some piece of mall junk. I checked the Cold Steel catalog I had handy and all their katanas seem to have fullers too.
As far as the term blood groove goes I believe I have an answer. With anything there always have been two terms. The technical and the common or slang term. I've worked in the electrical and communication industry my whole life. All our test and construction gear always had two names. The catalog and the common. IE a 76c dial set was worn on the hip and used to monitor lines it was called a buttinsky. Phone numbers were called drop because in the beginning a little door would drop and the operator would jack in and ask what conection you wanted. I could go on adinfonitum. I'm sure if you guys give it some thought you would see similarities in your own lives.
buckhunter: the katana is a slashing weapon
For what its worth the katanas that I saw while I was living in Japan had no fullers.
I never wanted to get close enough to see if it worked on a bayonet. Perfectly happy to use it opening ammo crates and C-Ration boxes.
with a bloode grove, it's easier to pullout. Check this out: http://en.wikipedia.org/wiki/Fuller_%28weapon%29 - Gian @ http://www.tealightholdersguide.com
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