Blood Groove: What is the truth behind it?

[SpyderEdgeForever]

I am sure many of you have seen numerous knives, daggers, bayonets, swords, and other cutting tools over the years that have the claimed "blood groove", the concave channel down the center of the blade, that is claimed to be put there to make it easier for blood to flow out of a target during combat. What is the truth of this? Does that stand up to known real world history and use, or is it just a gimmick for sale, or, at best, a way to lighten a blade?

Someone once told me that regardless of whether it works or not, it lightens and even strengthens the blade. I dont know if that is true or not. Does that hold up geometrically?

[dsvirsky]

The function of a fuller (not blood groove) is to lighten the blade while maintaining structural strength. Period. It's not there to channel blood or make it easier to withdraw the blade after stabbing someone.

Oh, and it also looks cool.

[Doc Dan]

Exactly.

I do not know why someone in their ignorance (or perhaps on purpose to make knives more evil) started that nonsense. Maybe it was just to impress others with their vast knowledge. It is actually a fuller. On a sword, it makes the sword able to be lighter, more flexible, and still remain strong. On a knife it is not normally necessary, but every ounce of weight savings can make a difference to a soldier or hunter. Marble's made their Ideal knife that had broad fullers on each side. It made for a very light, but strong knife for its size. They popularized the idea. Kabar copied the idea for their famous knife, but made the fullers less broad. Others have copied this idea.

[Reference_Sensor]

The above posts nailed it exactly. Bloviating journalists and Hollywood writers probably had more to do with this kind of folklore being propagated than anything else.

[MichaelScott]

The famous galdius hispanensis Roman short sword, was designed primarily as a thrusting weapon used in conjunction with a large shield. Early ones were about three feet, later shortened to the standard blade of about two feet. Very sharp point, no fuller or “groove”.

[cbrstar]

You can lighten the blade 25-35% without compromising strength. But I think the blood groove myth is because it's usually found on a weapon that's designed for stabbing and not cutting. You're not going to usually see one on a kitchen knife that's designed for slicing.

A lot of people say the suction thing is a myth. But this is going to sound gruesome...My Grandfather once told me in WW2 he had to fire a round to dislodge his bayonet. These myths all come from some truth.

[fanglekai]

A fuller allows the blade to be made thicker, thus stiffer and stronger for the same weight as a blade without a fuller. Removal of some material lightens the blade while maintaining the additional strength due to the increased thickness.

[Doc Dan]

A knife is not going to get stuck inside a body unless it gets wedged in a bone, which can easily happen. I knew a guy who stabbed a deer to death (his rifle malfunctioned) and the blade never got stuck. Look at all of the people stabbed. If this was a real concern, it would be well documented. It is an urban myth.

Now, I can see a saber getting, not stuck, but harder to pull out because the greater length would cause greater friction in a body. It would still come out with a yank. A rapier or foil, never.

[demoncase]

Funnily enough I've always called them 'fullers' rather than 'blood grooves'....They are there for the same reason structural steel in buildings are I-Beams or hollow box section.

It also means that the point of balance of a longer blade can be tailored to be more usable- a reason why they are such a feature of martial blades (that will be getting waved about a lot) rather than kitchen blades of similar lengths (which will not be getting waved about but used against a block- unless you've upset the Gordon Ramsay)

I have in my collection a 1907 SMLE Bayonet that was dug up at the Somme in 2007
Being the original pattern it has a hooked quillon guard
Even though it's 18" long and has a 5" handle- the fuller runs most of the blade, leaving the balance of the blade right around your index finger where it would be through that hooked quillon.....which isn't a surprise as the pre-WW1 army manuals featured a delightfully quaint section on 'fencing with the bayonet unmounted'.

Most of these bayonets got that guard cut down in 1914 when it was realised that the Great War was not going to involve the gentlemanly art of fencing.

[Backwoods92]

It's actually to help the blade come out easier after stabbing a body. Example is from the knife blade without a groove and being cold once it enters the body the hot skin and blood makes a Suction like effect to the blade sometimes making it hard to pull out and sometimes getting stuck. So moral of the story is always carry 2 knifes incase you get it stuck.

[Michael Janich]

Dear Backwoods92:

Welcome to the Spyderco Forum.

Unfortunately, you've been misinformed. The early posts on this thread are correct.

Stay safe,

Mike

[RustyIron]

What is the truth of this? Does that stand up to known real world history and use, or is it just a gimmick for sale, or, at best, a way to lighten a blade?

Fluted blades were a scam first perpetrated by those shifty Clovis people after they invaded by way of Beringia and started decimating our beloved mammoth population. The Folsom folks bought into this line of nonsense and used the blades to murder the noble bison. Unwary consumers have been falling prey to the fluted blade hype for over 13,000 years.

Clovis52.jpg (42.33 KiB) Viewed 3307 times

[shunsui]

My own experience was a history teacher in high school who talked about bayonets and suction. Of course with the introduction of the internet nothing is true anymore. Personally I understand being critical of anything on the internet but I find that goes double for "fact checkers" the last few years. I did a little Googling and the thing I noticed is there never seems to be any proof for the claims. One fellow said tests were run and no suction noticed. No reference was given, but I wondered how it was they found test subjects who wanted to be stabbed with bayonets. Stabbing a dead body doesn't seem the same as stabbing a 6'4" 250 lb linebacker type who is trying his best to kill you. Some people talked about muscle contraction and the hydraulic effects of liquids, i.e. blood. If anyone has some links to medical information on live bodies I'd be grateful.

[Naperville]

My own experience was a history teacher in high school who talked about bayonets and suction. Of course with the introduction of the internet nothing is true anymore. Personally I understand being critical of anything on the internet but I find that goes double for "fact checkers" the last few years. I did a little Googling and the thing I noticed is there never seems to be any proof for the claims. One fellow said tests were run and no suction noticed. No reference was given, but I wondered how it was they found test subjects who wanted to be stabbed with bayonets. Stabbing a dead body doesn't seem the same as stabbing a 6'4" 250 lb linebacker type who is trying his best to kill you. Some people talked about muscle contraction and the hydraulic effects of liquids, i.e. blood. If anyone has some links to medical information on live bodies I'd be grateful.

I believe everything in this thread until I poke a hog, wild boar or some other animal and try to retrieve it. Human combat is a funny thing and everything may be different from one stab to the second stab, as the human may be wearing something that creates the resistance to the thrust and draw.

Your best bet is to find a wild boar hunting forum and ask them what they encountered and report back. But that will have to do with wild boars and not humans because the body cavities, skins and coverings are totally different.

[JRinFL]

Considering how many stabbings are done with kitchen knives around the world , none with fullers (I refuse to repeat the silly phrase), I find the whole concept of suction causing the blade to get stuck to be ludicrous. But I’m just a guy on the internet.

[Ankerson]

Dear Backwoods92:

Welcome to the Spyderco Forum.

Unfortunately, you've been misinformed. The early posts on this thread are correct.

Stay safe,

Mike

Mike,

You know the thing about Urban Legends is they die hard.

And there are a lot of them about knives etc.

Tell an idiot or an ignorant person a lie enough times and over a long period of time it becomes gospel and truth.

One of the flaws in human nature that makes people so gullible, tell them what they want to hear and want to believe and they will believe it and swear by it no matter how impossible or full of crap it is.


Jim

[Doc Dan]

This myth of the blood groove ranks up there with bigfoot and the tooth fairy.

[hereiamu1]

This myth of the blood groove ranks up there with bigfoot and the tooth fairy.

[Ankerson]

This myth of the blood groove ranks up there with bigfoot and the tooth fairy.

Yeah, at least.

[bearfacedkiller]

The late Cliff Stamp once said that doubling the thickness of a knife quadruples the strength while doubling the height of the blade only doubles the strength. A fuller let’s you have a thicker blade and still reduce some weight.

When looking at things like swords, balancing weight and durability is huge.