Bayonet Blood Grooves

T

tsafa

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Nov 30, 2008
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I am trying to research the origin of blood-grooves on Bayonets. I am familiar with the use of fullers which look similar to blood grooves on swords. On a sword the purpose of a fuller is to remove weight in such a manor that it does not significantly weaken the blade. I do not think weight is significant on a knife or bayonet.

I had seen a documentary going back about 10- 15 years that said blood-groves were used to allow for "suction relief". I don't remember what people it was talking about but the era was pre-WWI and the people were Eastern European. From them the use of blood-grooves spread to bayonets in other armies.

Can anyone confirm the purpose of blood-grooves on knives and their historical development. Thanks in advance.
 
Swords with fullers after being thrust through someone would have also encountered this so called suction correct? Actually yes and no. The body is under pressure not under a vacuum which is why blood squirts all over the place when a major part of the body is lost. This so called "suction" is not really suction at all but is in part do to the bone swelling around the blade which causes it to stick. Removing the blade quickly after piercing bone will help to prevent this. If the blade becomes stuck twist it a bit to free it.

I can't confirm this but bayonets like many government designed things are sometimes done by committee. And someone on the committee probably thought it looked good so they had it included in the specification. I have never really been able to figure out any specific purpose for them other than looks. I will add that yes the fuller is used in a stiffening capacity on swords however, it's probably not really needed on all designs but rather may be just added to some designs. Some testing would be needed to determine their importance to the overall design.

You might try finding the original specification it might explain the thought behind them.
If you find something definite please post it.

Good luck.
 
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It serves two main purposes if memory serves me correctly. It does lighten the blade, not a huge amount but enough to be significant on the end of a rifle (nominally anywhere from 15 to 30%). Second it makes the blade stiffer which is important in a thrusting weapon.
 
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I believe that "blood Groove" is a misnomer. Fullers allow a lighter blade, but also make a stiffer and stronger blade. This is similar to corrugated metal sheets that are stronger and stiffer than flat sheets. Fullers were already used on military blades and when the bayonet was invented, ( in Bayonne, France) fullers were also used, in bayonets, for the same reason.
 
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On the longer bayonets I can see the need for weight reduction and stiffening but on some of the shorter ones I wonder.
 
Fullers can also serve to expose the edge. It removes part of the blade slope, making it easier to sharpen the blade. Marbles was particularly adept at doing this right.

Bayonets are a very interesting subject. Their entire history spans just 300 years; and during those years they experiment with just about everything that has ever been done with an edged tool. But, in addition to that, they are a decorative element of military dress, subject to whatever fashion symbology was favored at the time.

n2s
 
Fullers lighten but laterally weaken a blade compared to the same blade without one. They NEVER EVER EVER make a blade MORE rigid. That's like saying that a 6"x6"-ended "I" beam is more ridgid than a solid-ended 6"x6" bar. ;)
 
Absintheur said:
It serves two main purposes if memory serves me correctly. It does lighten the blade, not a huge amount but enough to be significant on the end of a rifle (nominally anywhere from 15 to 30%). Second it makes the blade stiffer which is important in a thrusting weapon.
Click to expand...

Your memory serves you well, sir.


http://www.agrussell.com/Articles/a/106/
Right Answers:
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
​
 
knarfeng said:
Your memory serves you well, sir.


http://www.agrussell.com/Articles/a/106/
Right Answers:
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
​
Click to expand...

The teerm "Blood Groove" is a sales tool meant to sell knives, it has no other purpose. The fuller, on the other hand is just as said above.

documentaries that say otherwise are made up by the ignorant who have never seen a bayonet in use.
 
Hey Mr. Russell,

HAPPY NEW YEAR TO YOU AND YOURS.
 
Time and again here, we hear military personnel warning against sending great big heavy knives to new troops because they will be carrying so much that every unnecessary ounce is unwelcome. I know that's how my police officer brother in law feels about his belt -- it's got enough on it already.

Lighter is better. As Absintheur pointed out, on the end of a rifle, the weight of a bayonet is more significant than in hand.

As for fullers on swords possibly inspiring fullers on bayonets, I have an old French bayonet that's about 18" and I wouldn't be surprised to see sword designs isnpiring bayonet designs at that length, although mine is a t-section.
 
I am wondering about fullering actually stiffening the blade. Does it really stiffen the blade? or just lighten it. I think it functions like an I-beam. Arranging the three plates of mettle in an "I" makes the beam stronger then if the three plates were stacked on top of each other, but not stronger then if you had a solid steel bar in the same dimension. It would weigh 10 times or more and use that much more material. Another way to look at it is if you had two solid steel plates and you fullered one. Can the fullered one actually be stiffer then the solid one? This does not make sense to me. I know that heat-treatment can stiffen mettle. That makes sense because the molecules are actually rearranged.
 
tsafa said:
. Another way to look at it is if you had two solid steel plates and you fullered one. Can the fullered one actually be stiffer then the solid one? .
Click to expand...

If you grind the fuller (Remove steel) you will make it ligther, not stiffer.
If you forge the fuller (Not removing steel) you will make it stiffer, not ligther.
 
Another think a fuller can make the overall cross section thinner, making the blade better for thrusting and slicing. Thinner blades although more fragile pierce and slice deep better.
 
Happy New Year, to AG, Esav, and everyone at Bladeforums.

The reasons for a "blood groove": balance, minimize weight, aesthetics.

It does lighten the blade, not a huge amount but enough to be significant on the end of a rifle (nominally anywhere from 15 to 30%).
Click to expand...
The weight savings might only be slight, but that could be enough in some cases to significantly affect the blade-handle balance when handheld. Not sure either if it would make much difference when mounted on a rifle.

The subject is fascinating...
 
FortyTwoBlades said:
Fullers lighten but laterally weaken a blade compared to the same blade without one. They NEVER EVER EVER make a blade MORE rigid. That's like saying that a 6"x6"-ended "I" beam is more ridgid than a solid-ended 6"x6" bar. ;)
Click to expand...

actually, the 6x6 i beam is more rigid than a solid 6x6 square beam. it may seem counter intuitive because you're removing material, but it actually makes it stronger because it decreases the geometric moment of inertia about center of mass

http://en.wikipedia.org/wiki/Beam_(structure)#General_shapes

so the fuller would make the blade stiffer
 
knarfeng said:
Your memory serves you well, sir.


http://www.agrussell.com/Articles/a/106/
Right Answers:
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
​
Click to expand...


Quoting someone else's comments is not scientific prove. Where are the facts and figures? I would really like to see hard evidence in the form of mechanical engineering test data to support your point 1. I have seen the stiffness argument ongoing for years but no scientific evidence to back it up. I still contend that because a fuller lightens the blade, it allows a thicker blade of the same weight. It is the extra thickness that gives it the stiffness and not the fuller itself. I have never seen any scientific evidence that proves 2 blades that are identical except for one having a fuller display a difference in their stiffness. An I-beam works because of the extra width of the horizontal ends and not because of the thinness of the perpendicular. A rolled spine in an oildrum works because it effectively makes the steel wider at that point.

I do not accept the "double spine" argument - the blade is thinner at the fuller, not thicker on the body - there is no "double spine". The only possible way I can see a fuller making a blade stiffer is if it is forged in such a way that the grain direction of the steel is altered in directions that will stiffen the steel.

I have never seen a rifle manufacturer claim that fluting a barrel makes it stiffer. They will claim that it makes a thicker and therefore stiffer barrel lighter.
 
Quoting someone else's comments is not scientific prove. Where are the facts and figures? I would really like to see hard evidence in the form of mechanical engineering test data to support...
Click to expand...

With regards to historic artifacts like bayonets, it isn't necessary to prove the effectiveness of such theories, only that makers and designers believed in the possibility.
 
The deflection of a beam is inversely related to the flexural rigidity, EI, where E is the elasticity of the beam, and I is the geometric moment of inertia, or the second area moment.

The fuller makes it so that more of the mass of the blade is concentrated outwards, from the center of mass, so that the moment of inertia is higher. This increases the flexural rigidity of the beam, decreasing the deflection.

I'd give more detailed formulas, but they're hard to type out, and they vary depending on the amount of load and the particular distribution.

so it isn't exactly the extra thickness of the blade, but the fact that the spine is thicker than the fuller. I shaped beams are more resistant to bending than just an l, for example. That's why beams are often made in the shape of I's, C's and U's

hawkings is right. if you simply grind out steel, it won't be stiffer
 
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