What is a blood groove for

M

mickh

Joined
Dec 2, 1999
Messages
4
I have seen blood grooves on alot of knives but I never knew what the real purpose of them was.
 
i thought to increase the strength?
am i wrong?
 
The real reason for a bloodgroove on a blade is so that posts like this can keep starting up every month or so to ask "What is a bloodgroove for?". Ask 10 people get 10 different answers when all it really is is a conversation starter. If the thing was called an "Air Channel" or some other mundane thing instead of "BLOODGROOVE" no one would ever question it. Maybe it belongs in the new edition of Modern Urban Folktales right along side some other greats like The hairless Mexican dog(rat) etc etc.
Bob
 
I have wondered about the purpose of a blood groove too. I am going to suggest, though I am not sure, it is a matter of physics. I think the blood groove may exist to enhance penetration by providing a channel for blood to escape the body. This relieves pressure in the wound allowing the blade to penetrate more easily. If this sounds preposterous, I apologize. It is just a thought.
 
i feel that it is just for looks may make the knife lighter but really i cant see it happening. Also on my Buck special all it does is collect blood and get all full of gunk.
 
The blood groove is there so that if you stab someone they will bleed faster, rather than having the knife plug up the wound.

The blood will flow around the grooves. You see?

That's why you tend to see them on "combat" knives.

What, you don't believe it? Shows how much you know!

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Happy Holidays
 
Your half-right. Blood grooves originally appeared on swords and the reason is physics; but not to do with driving the blade deeper. When a sword or large knife enters the body, specifically the chest cavity, you get what's called a "sucking chest wound". The inside of your body is like a sealed unit, think of it like a plastic bag. When you break the seal the body tries to close the wound sort of like a vacuum effect. The knife or sword actually acts to seal the wound and so gets stuck (this is why first aid courses allways tell you not to remove the knife from a stabbing victim, the knife is actually preventing external blood loss). With blood gooves, the body can't seal around the knife or sword and so the weapon can be removed more easily. Nasty, but effective.

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"Better to reign in Hell, than serve in Heav'n"
John Milton
There are only two types of people; those who understand this, and those who think they do.
 
OUCH! it almost hurt to read that
wink.gif
 
Guys, this has been discussed ad infinitum in these forums. I can just hear a lot of folks saying "oh no, not this one again." I'll try to give you the answer this time. Use the search function to check out previous answers to this question. It is amusing to me how a modern marketing ploy can become something almost like religious dogma.

Simply, the 'blood groove' has nothing at all to do with blood, or suction, or anything like that at all. In ancient Japanese swords, those of superior quality had a very wide groove gouged out near the spine of the blade. It is more properly called a 'fuller'. This lightens the blade and makes it faster without losing any structural integrity, kind of like the steel I-beam's used in construction. In modern hunters and fighters, the groove was added mostly for decoration and has become so small (narrow) that it serves no functional or structural purpose.

If you don't believe this, check previous threads in this forum, and read magazines like Knife World, which ran an article on this topic recently, including a historical perspective of the marketing campaign by Marbles Corp earlier this century in which this idea of calling a small fuller a 'blood groove' first appeared in this country. Early on, some companies used very wide fullers on hunting blades to lighten them. Over time, the fuller became smaller and smaller until its presence did nothing for blade performance at all. It's is purely decorative and nothing but marketing hype!

Although it does Sound logical, there is no suction pulling on a blade inserted into a body cavity. A blade with or without a 'blood groove' will seal the wound around the knife from tissue pressure and a small amount of blood. the pressure in the interior of the body is not negative relative to the outside air. It is the same. It is a good idea to leave a penetrating knife where it is until you can seek proper medical attention. Once the blade is removed, the rate of blood loss will increase dramatically. Although for most deep penetrating wounds involving major arteries, I doubt there would be enough time to get life saving medical attention in any case.

Paracelsus

[This message has been edited by Paracelsus (edited 06 December 1999).]
 
Paracelsus is correct!

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David Gardner
Vineland NJ

"If you fake the Funk, your nose will grow."
-W. Bootsy Collins


 
Joe,

Loved your blade FAQ articles. I read them some months ago, and I just rescanned the whole section again. However, I am Not finding any blood groove or fuller information. But then, maybe that's the idea?
 
The fuller on the Russian Sabre I bought was purported to be for weight reduction and stiffness.

I'm not sure about the stiffness deal - I know sheet material will resist bending if in that shape ("H" beam secion if you've a good imagination). Perhaps someone out there would know if stiffness is actually improved in solid stock.

I had several pieces with "fullers" long before I ever heard the term "blood groove" - does this term have any origin apart from some marketing guy?

Stiffness on an 8" blade would have to be a non-issue. The looks of the fuller on the Junglee Hartori, IMO, arean't at all bad even if not needed from a functional standpoint.

"Hamon" - invisceration depth gauge?

JH
 
What?? No blood groove article?

Okay, do this. Go to www.deja.com, hit Power Search, put in FAQ for subject, rec.knives for Newsgroup, and Joe Talmadge for Author.
You'll get all the latest FAQs, including the blood groove FAQ. Sorry, I thought the Blood Groove FAQ was up here.

Joe
 
My understanding is that the fuller is there to reduce weight w/o while retaining most of the original strength. Sort of like an "I" beam. If you look at thrusting weapons, like spears, arrowheads, thrusting swords, they usually have no fuller. But cutting swords like samurai swords and Viking swords did.

So here's a question. Would a fullered blade be significantly weaker in lateral strength? Because when force is applied laterally to a blade, a fullered blade will act like an "H" beam. And nobody uses "H" beams in construction.
 
There is no such thing as a "H" beam there all "I" beams and in construction you would rotate one 90 degrees to get a visual "H" the idea being that these 2 columns in differing rotations have the best of both worlds where the stresses would be minimized do to the differing rotations. It's called wind loading.

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~ JerryO ~

Cogito Cogito Ergo Cogito Sum


 
I suppose that makes sense when you're building with hundreds of beams.

What I meant was, isn't an "I" beam desinged to take more force from one direction than another? When you are using a single "I" beam, you lay it in a way that the force pushes down on top of the "I", not to the sides.

Some have said a fullered blade acts like an "I" beam. Weight is reduced without much loss of strength. But isn't that blade going to be able to take less force laterally because of the fuller?
 
If lateral force were the only concern swords with a diamond cross section would be best, having one structure to resist lateral force and making it maximal thickness. The advantage of fullered construction is it resists twisting forces better than a diamond construction, which can be important in a sword. Knives do not have a problem with twisting forces so in a knife, a fuller serves no real purpose but decoration.

-Cougar Allen :{)
 
I have to agree the blood groove serves no purpose. The suction idea sounds good, but i'm pretty sure its not true. The reason a sword will seem stuck in the body ( greusome thought) is that the muscles contract around it very strongly. When the blade enters the body the nervous system naturally tenses everything and the muscles lock up.Its just a natural reaction of the body when it goes into shock. Have you ever hit your funny bone and had your fist lock closed for a few seconds? Same idea.

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Fix it right the first time, use Baling Wire !
 
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