- Joined
- Aug 11, 2001
- Messages
- 3
I am having a sort of debate with my finacee about the function of grooves in the sides of knives. I am sure someone here knows what they are for. Please let me know what ou think. Thanks!
-
The BladeForums.com 2024 Traditional Knife is ready to order! See this thread for details: https://www.bladeforums.com/threads/bladeforums-2024-traditional-knife.2003187/
Price is$300$250 ea (shipped within CONUS). If you live outside the US, I will contact you after your order for extra shipping charges.
Order here: https://www.bladeforums.com/help/2024-traditional/ - Order as many as you like, we have plenty.
"grooves" in the sides of blades...
- Thread starter OutlawGirl
- Start date
- Joined
- Mar 26, 2000
- Messages
- 658
"Grooves", unless you are talking about cosmetic fullers to show off damascus patturns, blood grooves in fighting or combat knives, do what there name implies. They also lighten the blade and balance it. Structurally groves "may" also strenghten or stiffen a blade like roman building collums or fluting on a rifle barrel.
What possibilities are yous arguing about. If yous are both right go out and buy each other a new knife.
Welcome to the forums. Nice to see more of the "fairer sex" here, but with your handle I could be wrong.
What possibilities are yous arguing about. If yous are both right go out and buy each other a new knife.
Welcome to the forums. Nice to see more of the "fairer sex" here, but with your handle I could be wrong.
- Joined
- Aug 27, 1999
- Messages
- 4,531
Welcome aboard!
Generally, grooves in the blade are there to lighten the blade. This not only reduces the weight, but aids in balance and stiffness. Stiffness is aided in a similar way to the way that corrugated sheet metal resists bending better than a flat sheet of metal would.
Generally, grooves in the blade are there to lighten the blade. This not only reduces the weight, but aids in balance and stiffness. Stiffness is aided in a similar way to the way that corrugated sheet metal resists bending better than a flat sheet of metal would.
- Joined
- Aug 11, 2001
- Messages
- 3
Ugh, I lose AGAIN! Thanks R Dockrell. But I'll probably keep the info to myself heheh. I figured he was right, but he can never prove anything lol.
Anyways, thanks for responding! This is a cool board.
Anyways, thanks for responding! This is a cool board.
The reason you want Blood Letting Groves is, when you extract the blade from your attacker there is a suction which works against the easy removal of your blade from their body.
I know this from watching TV programs such as A&E's Investigative Reports and other shows about crime case etc...hearing about autopsies preformed on stabbing victims.
I know this from watching TV programs such as A&E's Investigative Reports and other shows about crime case etc...hearing about autopsies preformed on stabbing victims.
- Joined
- Aug 11, 2001
- Messages
- 3
That's exactly what we were talking about. He was telling me that they were so you could pull the blade out easier, if you were in a battle, or whatever. For some reason I doubt him, must be the smirk he gets on his face, and i just HAVE to prove him wrong! Oh well! 
Gollnick
Musical Director
- Joined
- Mar 22, 1999
- Messages
- 29,258
Take a piece of ordinary notebook paper, 8.5x11". Try, please, to grip it between your thumb and index finger along one of shorter sides. Now, try to get the paper to stand out horizontally. Once you've satisified yourself that it's not gonna happen, fold the paper in half the long way. Now, try to hold the page out horizontal again. No problem, eh? You haven't changed the paper's material or thickness, so why is it so much stiffier?
That's what a "fuller", sometimes called a "blood grove", does to a blade. The interesting thing about doing this on a blade is that you're actually removing material. So, the resulting blade has less material but is still stronger and stiffer.
That's what a "fuller", sometimes called a "blood grove", does to a blade. The interesting thing about doing this on a blade is that you're actually removing material. So, the resulting blade has less material but is still stronger and stiffer.
- Joined
- Nov 24, 1999
- Messages
- 4,981
Sorry but I don't think thats right. We had a huge debate about this some time back, its in one of the archives. It took a lot of arguing but the general consensus came to be that "blood groove" is just a name someone came up with to make it sound cool and sell more knives. The only real function of the groove is that it stiffens the blade laterally. The so called "suction effect" is actually from the muscles spasoming and sort of clamping down on the blade.
- Joined
- Oct 3, 1998
- Messages
- 4,842
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.
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
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...
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.
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
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...
- Joined
- Nov 6, 1999
- Messages
- 2,639
I mananged to find the old monster blood groove thread in the archives. For more information than you ever thought possible on blood grooves, steel smithing, history, anthropology, and modern marketing, see this great thread: What are blood grooves for?
Paracelsus
Paracelsus
- Joined
- Apr 30, 2001
- Messages
- 1,742
Jim Hrisoulas and I talked for many hours about this very subject a few years back. Many consider Jim to be a bonified expert in the area of the forged sword and the history of such.
The end result.
The fuller is only to lighten and to make a blade stiffer (much as an I beam).
The whole vacuum thing holds no water. If the muscle contracts, it will fill in the fuller as well making it in that use, useless.
The end result.
The fuller is only to lighten and to make a blade stiffer (much as an I beam).
The whole vacuum thing holds no water. If the muscle contracts, it will fill in the fuller as well making it in that use, useless.
- Joined
- Mar 10, 2001
- Messages
- 2,033
Gentlemen:
It is really very simple.
Fullers are to lighten and stiffen blades
Blood Grooves are a sales tool: They look cool, and they catch the imageination of those who think they know what they are for.
I used to think that it was important to tell people the truth about fullers, I found that I was killing sales. If people want to belive in blood grooves, let them. Do you want someone telling your kids that there is no santa claus?
just my .02 worth
A. G.
It is really very simple.
Fullers are to lighten and stiffen blades
Blood Grooves are a sales tool: They look cool, and they catch the imageination of those who think they know what they are for.
I used to think that it was important to tell people the truth about fullers, I found that I was killing sales. If people want to belive in blood grooves, let them. Do you want someone telling your kids that there is no santa claus?
just my .02 worth
A. G.
- Joined
- Apr 3, 1999
- Messages
- 2,052