I was told the grooves on a bayonet was so it was easier to pull back out of the body, specifically in the stomach muscles. The grooves you see on those blades is purely for looks or to take weight off I guess but I don't see that being why you see them on blade very much designed to kill in the most efficient way
@@user-fc7wg7ix8y that just doesn't make any sense. How and why would that happen? The fuller doesn't affect anything that much. Why would it suddenly be so much hard to remove the knife if it hasn't got a fuller? It doesn't change the surface contact significantly, so friction changes are negligible. If anything a fuller would increase surface contact and make it harder to remove by giving additional surface for the flesh to grip onto.
Hey so blacksmith here. So I can't remember the exact manual that states it but there is a historical recording for daggers explaining that a secondary use or rather added benefit for the Fuller in the blade is the allowance of blood to flow to aid in the removal of the dagger as not to get stuck in the body due to the adhesive force of blood and the internal suction caused by the sealing of the wound. An interesting experiment to test this out would be to take a piece of ballistics gel with a blood pack in it and stab it with two different knives of the same relative blade shape, size, and length. One with a fuller and one without a fuller.
I think a better test would be to stab block with blood and one without using the same blade. This would be better (imo) as the blade acts as a control variable. And seeing as though the claim is about the interaction between the fuller and the blood it makes sense to test with or without blood instead of different knives.
@@devrajryatt I like the Introduction of the additive variables but a small issue I see is say for example a blade with a different shape than the blade with and without the fuller has a different interaction with the ballistics gel and the blood, how do we go about proving that that blade shape wouldn't benefit with a fuller as well? I feel like if we were talking specifics about a specific knife design, shape, point geometry, etcetera. Then the introduction of different knife shapes would be more relevant to the test. But the test is for the effect of the Fuller in the interaction with the blood. Now here's my kind of suggestion to your suggestion or rather my compromise. I say let's do this test with multiple sets of knives with varying shapes but two knives for each set one with and one without a fuller and we use the data across all the knives to come to a agreed result
A fuller, which is a groove or slot cut or forged into the flat side of a blade, can both lighten and stiffen a sword while maintaining much of its strength. The geometry of the fuller's shape helps to maintain strength, even though cutting or grinding a fuller into an existing blade will remove some material and decrease its absolute stiffness.
Exactly 💯 And any bladesmith would agree. These people here in the comments insisting that it's grove meant to allow blood to flow out, or reduce suction on the blade so it's easier pull out after stabbing someone, doesn't know what they are talking about. It's only function is to reduce weight while maintaining strength and structural integrity of the blade.
I thought the "blood groove" was supposed to make it easier to pull the knife out during combat. It's supposed to prevent the suction effect by giving the blood somewhere to go.
It's a myth that keeps getting reiterated over time. Fairbairn-Sikes for instance was built purpose for thrusting (and some cutting) and it worked exceedingly well without fullers. Fullers or not, any blade stuck in bone can have issues being removed and grooves won't make any difference.
The blood groove has been debunked several times but people still insist on calling it that. Still, it is cool seeing the Diphos in action. Any chance we get to see a full length video of it in action?
I remember learning about those when i looked into smithing techniques. Rangeing from Groves to actual holes. Depending on your designs and if it will retain its strength when the metal is thinner or removed. It was all to reduce weight w/o sacrificeing durability so it could be used in combat longer.
As far as I am aware they are called blood channels where this applies to especially military daggers or bayonets and it has nothing to do with causing greater bleeding, it mitigates suction allowing for an easier/faster pullout so you can repeatedly plunge the blade.
Blood groove isn’t to inflict blood loss, but to make it easier to pull out of combatant you stabbed. If it’s just a flat blade then the pressure on the blade while in the body would make it harder to retrieve. A blood groove however like on bayonets or Kabars is meant to add a little bit of air to keep the pressure from acting like a vacuum on the blade, making it easier to pull out and stab again
A fuller can also make the blade more rigid but adding planes to the profile of the blade that won't bend as easily if at all. Thrust dominant swords may have differing profiles, but a fuller allows you to widen the blade while maintaining a high level of rigidity.
The profile of the blade does have some influence on how much blood loss you can inflict. For example, diamond shaped knives, like daggers, can inflict wounds that can't close on their own and will obviously cause significant blood loss. But unless you are unconscious, you will plug that wound immediately and mitigate the difference.
Absolutely love my ZombieTools blades. My favorites are the gladius and the persian fighting knife, but they're all awesome. That video of them chopping the hood of a car in half with a sword sold me lmfao. Their blades are TOUGH ZT specifically states they are not blood grooves, but are in fact fullers as you said.
another big reason they are there is it adds strength and rigidity. the same as a bar versus a pipe with the same amount of material. the extra surface area adds a lot.
Before I started educating myself in the making of bladed weapons, I was always told they were blood groves & was told their purpose was to prevent the blade from getting stuck in the body. By providing a channel for air to break the vacuum the body creates around the blade.
If you ever seen flat support brackets they generally have this same thing and it's to make it more stout under pressure. Maybe not the reason on blades but I'm sure it does the same.
Blood grooves were added to knives/swords to make removal easier. Suction from closing flesh prevents a flat blade from removal. Blood grooves break the suction area.
The whole reason behind that groove serves multi function is to a reduce the weight of the blade, but also be to make it easier to pull out when stabbed into something. For all the people in here saying that’s not what happens when you stab something, you're right when you use a small knife but that's why you don't see small knives with a blood grove/filler. A knife like a K-bar or a bayonet or any knife over 6inces is a little bit bigger than a pocket knife. With that much thickness and length yes there will be some friction/suction and that grove helps pull the knife out by breaking the seal. The reason it works is because 9 times out of 10 your not going to get the whole knife inside of whatever your stabbing with a knife that big that's why it is where it is on the blade. However, how he tested it on the video is not how it is meant to be used at all. It's not meant to inflict more damage it simply makes it easier to pull out of some thing, and reduces the weight of the blade a little bit.
The grooves are designed to allow you to pull it out. When pierced muscle clamps down on the weapon. The groove allows the muscles to release blood so the clamping effect is weakened. It's for pulling out your blade. Nothing to do with increasing blood loss from the wound. A removed blade leaves a large incision to bleed out
They’re nice people and will continue to be nice people as long as you endorse or keep on paying them. Blood grooves are essentially gutters to make it easier for the weapon to move through the target w/less friction - physics
I've heard the claim the fullers are there to keep the blade from getting stuck through suction. Also, in some swords, the fullers also add a bit of strength to the blade.
The blood groove is not to increase blood loss: When you try to pull out your knife, it would create a partial vacuum which makes it harder to pull out. The groove allows for air to flow into the wound, preventing a vacuum and making it easier to pull out the weapon.
I thought those grooves are there for the pullback out of the body so that there is no vacuum and the knife won't stuck in the flesh. Don't really know if that is true though.
It's not. That would require the body to have a negative internal pressure. If that was real, you also wouldn't bleed because your own blood would get sucked back in. Blood comes out because you're internally pressurised, by having a beating heart.
Always thought its main purpose was to reduce weight. Just also happen to help with letting blood spill a bit out lol. Like, why can’t it just be a byproduct? Kinda like a compensator/flash hider/muscle break… they all have their specialized purpose, but help with other things too compared to having nothing? Am i wrong for this?
That "groove" is dual purpose. It takes weight away, making it easier/faster to swing. It's also to allow air in as you remove the blade after a stab/thrust. This is to make it faster to remove from the target. You can take a knife without the blood groove/fuller and stab something (dead pig or a ballistic dummy) as an experiment/ test. You can still pull the weapon out sometimes fairly easily, but with the fuller/groove, suction and friction are reduced, and it becomes significantly easier/faster. This concept came around when the fuller in swords was not a common practice and other things such as arrows (which are a pain in the ass to remove) contributed to this theory.
I know you've done khukri's before but have you done a genuine made in Nepal 🇳🇵 khukri. Same kind that the ghurkas would carry into battle. A review would be cool. Thanks
The only explanation of why they were functional features aside from weight reduction that had the name "blood grooves" that I ever considered as plausible was as a vacuum/suction breaker.
The only thing I know that comes anywhere close to "blood grooves" is the (occasional) hollow-ground edge of an Indonesian Kris, and you're supposed to pull the Kris out. In order to cause more damage
Test it against a non grooved blade for best results. I can also see the groove being useful on a throwing knife against multiple targets. Deal additional blood loss while focusing on other targets to do the same then retrieve your blades after the battle if you're still alive to do so.
The fuller wouldn’t have really any positive for a throwing knife because they are made to be a certain weight, and not necessarily lighter. A fuller is pretty much just for making the blade lighter and more maneuverable, and it could mess up the throwing knives trajectory and reliability. That’s one of the reasons you don’t see them on any throwing knives (also because they are usually light enough that it’s not cumbersome to carry them, one of the reasons they were used in the first place)
@gandalf2447 possible solution is to extend the blade to compansate for weight loss in the centre. Longer blade also means deeper internal damage which is huge. Especially when the blade's groove passively starts to drain blood from damaged organs.
@@shreddernation1096 A longer blade effects the trajectory and balance. This is why a long sword/great sword feels really heavy when they actually don’t weigh much at all (the biggest swords possible to wield weigh a little under the weight of a baby)
@gandalf2447 Balance is based on weight not length. If you take weight from one side of the balance point which in this case is the blade's groove and add the same weight you took and used it to extend the blade this restores that the balance point to it's original point as the weight is still the same. Then you can forge a new blade based on that design in mind. On the topic of trajectory, it may take some practice to master the technique of throwing the new blade but it is achievable as throwing blades already come in all shapes and sizes.
Blood grooves are meant to make the knife easier to remove… stab it was a regular flat knife with no groove and you’ll notice it’s harder to remove that knife…
I thought the whole “blood groove” way of thinking was more to stop the flesh from closing around the blade and making like a suction seal, making it easier to remove. It’s bollocks like, they’re fullers to reduce weight but still. I thought that was what they thought not that it was to increase blood loss.
@@garethkalum8297probably shoulda said “mildly convincing” can’t remember the explanation just remember I heard it somewhere take it with a grain a salt sorta thing
@@smorgishborg7789 ok, but just think for a minute, if the fuller doesn't direct away from the handle, how is it going to direct blood away from the handle?
I wish I could get myself a Zombie Tool's sword. But I live in the UK and have no interest in trying to get one imported. Especially since there is an argument that could be made that it is a "Zombie Knife", and those, I shit you know, are specifically classed as illegal.
Now the so-called blood Groove when I was coming up 40 years ago not only it was explained as a fuller concept taking wait out of the blade, but also allowed the extraction of the blade to be easier, because apparently it was easier to put a knife in then to pull it out due to body suction. Thank God I never got to test that concept, and I don't know how you would.
I know how a fuller works, but the "ye old lore" I always heard was the blood groove was supposed to prevent suctioning of the blade in the wound. Easier to pull out , yada yada.
I remember being told blood grooves were made to direct blood flow away from your hand or something like that, not to bleed your enemy faster. I'm sure that's wrong, but it's still odd that the stories arecso different.
@@donaldgreen4382 Yes, indeed what I say. I don't know about you, but I haven't been able to find any historical texts that either study, nor mention this suction effect. You would think that of all the butchers, farmers, hunters, etc of those times, surely a couple of them would have documented the phenomenon, right? Well, it's not the case. Secondly, if this suction effect was indeed taking place, then it would have the greatest effect at the point where the blade is making the most contact with the flesh, which is the tip of the blade. Despite this, no functional blades are designed with a fuller that runs all the way to the tip, and it's not even close. Third. Severed muscle contracts towards their anchor point to reduce blood loss. This means that said damaged muscle is pulling away from the surface of the blade, which reduces what little friction there might even be. Fourth. All creatures are evolved to withstand the pressure of the environment they're in. This is best demonstrated by taking a look at a blob fish that has been taken up to the surface. It completely collapses because its internal pressure is now much higher than the external pressure pushing back on it. Furthermore, the blood pumping through our bodies is slightly higher pressure than it's surrounds such that it can be pumped through our body against other forces such as gravity. If you really wanted to get into the nitty gritty of it, the blood flowing from the wound would actually be helping to remove the blade rather than retain it on an absolute miniscule level.
I mean, i don’t know who thinks they are “for inflicting blood loss,” I always thought that they were there, besides reducing weight, to make the blade less likely to seal the hole it made, creating suction. E.I, to help you NOT leave you blade in your target.
I was told by the guy I apprenticed with that they were both. His explanation of a blood groove was drastically different though. He said it was more to try and keep blood off the handle so you could maintain grip, giving it somewhere else to go, and if it pools it's easier to sling it off the blade. Would love some feedback on that 🤙
That doesn't make even a single shred of sense. The fuller isn't guided away from the handle, so how would that happen? It's literally a straight Line from the tip of the blade to the handle. If anything it directs the flow towards the handle.
If you've ever dealt with a blade that has blood on it, you'd know that blood doesn't just flick off like water, it's sticky and viscous and will stain a blade if you dont wash it off and then dry and oil the blade. Blood grooves is a lie your master bought into and keeps unwittingly selling tonhis apprentices.
When I was like 4 or 5 my dad was giving me his pocket knife from the war, there was a small hole in the base of the blade, I'm sure to reduce weight, but when I asked about it he said that it was so that blood could drain from his knife faster, idk why I believed him
People who say it's for Blood Lost are completely out of touch with reality. Any person stabs 2-5 times a second, and the cavity doesn't matter how much it bleeds. And if the person is very experienced and is killing and not fighting, they'll turn around and take the knife out and walk away so the victim can't react. Under no circumstances would the knife stay in the person on purpose.
I had to explain to my step-parent that it wasn't a blood groove but a fuller. He called me a dumbass before I looked up the historical name for it being a fuller and still refused to believe me
