# Is this a good combat knife?



## PhotonGuy

So would this be a good combat knife?

SEAL Team


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## Mephisto

What do you plan on using the knife for? If you're not military or LEO than you don't really see combat. Regardless of your use, SOG makes great knives in my experience and my fellow knife enthusiasts say the same. If self defense is your goal though I'd find something else unless you live in a rural area, maybe a smaller SOG. One thing a lot of martial artists don't account for is what normal people carry and do. As a filipino martial artist this is especially true, we're knife fans and collect knives but it's it's important to remember that should you ever actually use a blade for self defense you'll want to blend in. A $300 specialty blade will look out of place, and while you may be legally defending your life the tides can easily turn, a trained victim can quickly become an assassin (which is illegal). If you ever kill with a weapon you want to blend in and look like a regular guy who found himself in unfortunate circumstances and came out on top. You want the jury to identify with you. If you're painted as an experienced martial artist killing machine you have less chance of escaping jail time. A specialty blade or anything that looks intimidating for the situation it was used can be used against you. The OPs example isn't too extreme but still doesn't fit in your average suburban setting unless you have good reason for carrying such a blade (hunting trip, recent camping, fishing tackle accessory). As a martial artist if you're trained to protect your life you should understand the realities of what might happen if you survive a deadly altercation. If your group portrays a "deadly" persona or uses "deadly" tactics as a marketing tool, it can be used against you if you ever defend your life at the expense of a criminal's. The "deadly" image might attract students and take in the $ but it actually might do a disservice to those that actually need the art.


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## Brian King

Really like the seal pup's, especially for training. Decent quality, feel, and price. 


Regards
Brian King


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## drop bear

Brian King said:


> Really like the seal pup's, especially for training. Decent quality, feel, and price.
> 
> 
> Regards
> Brian King



Yeah I have the seal pup elite with the fine edge as a camping knife and like it. From what i read the elite version of both knives is generally worth getting for the bit extra money.

Regarding the pup vs the full side seal One of the knife instructors up my way Paul Cale does the ghost. Which is a dedicated fighter. But not a big knife all round. So if op wanted a fighter that might be a bit more manageable for bushcraft that pup elite could be the better choice.

And I am not a fan of the serrated version of either. It gets in the way more than it helps.

And eBay. $160 is too much for that knife. Here is the elite version for a hundred.

http://www.ebay.com.au/itm/SOG-SE37...462?pt=LH_DefaultDomain_0&hash=item1c472e79ce


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## ST1Doppelganger

I wouldn't take a sog in to a combat scenario as my only knife if you were going to use it as an all in one survival and defense knife because they can easily be broken. Like a high percentage of knives out there they will break of you try to pry or leverage with it. 

Sog dessert dagger, pentagon and mini pentagons are my choice sog knives. 






These are my two mini pentagons that I picked to after learning the double dagger set and they sit in my bug out bag along with a buck intrepid and a spyderco police amongst other goodies.


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## ST1Doppelganger

I don't even know how the SOG Seal beat the Buck intrepid as a military knife other then the sole purpose of it being a good killing machine. 

This is my buck intrepid that I would use as my survival knife if everything went down the tube. 









Id be impressed if i broke this thing and its a very versatile knife.


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## realg7

PhotonGuy said:


> So would this be a good combat knife?
> 
> SEAL Team








Sent from my SAMSUNG-SM-G935A using Tapatalk


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## marques

--


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## Danny T

A good combat knife will have to serve multiple duties besides being an edged weapon.
Edge retention and ease of sharpening is a must as well as tensile and load bearing strength.
Many modern day 'combat' type knives look great, feel great but lack the multi task abilities of a great combat knife.
Can you dig a hole in the ground with your knife? Can you pry heavy objects with your knife? Can you use your knife as hand or foot hold for climbing without it bending or breaking? Can the edge be sharpened with a flat rock? Can your knife be strapped or tied to a pole and utilized as a spear for thrusting or throwing? Can your knife be used for chopping hard objects like small trees or being batoned with a stick or rock? Can you skin a small animal or do some small detail work like creating snare triggers with your knife?
A good combat knife, in my opinion, must have the capacity to do all the above to even be considered for being a combat or survival knife.


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## Charlemagne

My EDC knife is a Spyderco Manix 2.  It's an incredibly common pocket folder, with a deep choil, great jimping, and a very solid lock.  I have one of the sprint runs, so it isn't as common as some versions.  Why?  Because it is lighter due to the skeletonized liners, and I am an unapologetic steel snob.    When I want to carry a non-folding knife, I carry the Waid Covert, made by Brian Biegler.  Home 

The knife I wish I could carry is the Applegate-Fairbairn, as I love the double edge and the utility of the design. Unfortunately, daggers are not allowed where I live.  Even if I could carry it, the only one I know of making decent ones is Boker, and I probably wouldn't buy one from them.  Did I mention that I am a steel snob?


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## Edward Cullen

@Charlemagne: I have a Spyderco Manix 2 too. It's my favorite knife.


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## Charlemagne

Edward Cullen said:


> @Charlemagne: I have a Spyderco Manix 2 too. It's my favorite knife.



Good choice!  For an EDC folder, it's hard to beat.  

Though now with the new Texas knife law, I am free to carry double edged daggers, which are way more functional, particularly in Pikal grip.


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## Bino TWT

PhotonGuy said:


> So would this be a good combat knife?
> 
> SEAL Team



Looks good, decent steel. A few things to consider though... This "SEAL" knife has absolutely nothing to do with the SEALS; that's just clever marketing. It's made from Japanese steel and manufactured in Taiwan, so I would have concerns about the quality, especially the heat treat. It might be a good EDC, but for what it is, it's very overpriced. They actually sell this exact blade at Walmart much cheaper. 

For that price, I could make you a very nice high quality custom blade... just saying lol


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## Runs With Fire

If it has a handle, blade, and an edge then it should do the job.  It's nice if it fits your hand.  My big point, if you are gonna have a knife for emergency/ bug out or whatever, learn to sharpen it well.  A dull knife nakes for little more than a paint stir stick, fish scaler, and tent stake.  A razor edge isn't tough to achive, and it's simple to maintain.


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## Runs With Fire

For what it's worth, I use fixed blade knives alot.  I've broken a lot and lost a few, including my favorite,.  My bug out knife, woods knife are: 
blaze orange handle and sheath
Hard plastic sheath
Thick blade
Hole in handle for lanyard
Clip on sheath, as opposed to belt loop ( i often attach it to my backpack during trecks)


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## drop bear

Runs With Fire said:


> For what it's worth, I use fixed blade knives alot.  I've broken a lot and lost a few, including my favorite,.  My bug out knife, woods knife are:
> blaze orange handle and sheath
> Hard plastic sheath
> Thick blade
> Hole in handle for lanyard
> Clip on sheath, as opposed to belt loop ( i often attach it to my backpack during trecks)


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## dvcochran

Mephisto said:


> What do you plan on using the knife for? If you're not military or LEO than you don't really see combat. Regardless of your use, SOG makes great knives in my experience and my fellow knife enthusiasts say the same. If self defense is your goal though I'd find something else unless you live in a rural area, maybe a smaller SOG. One thing a lot of martial artists don't account for is what normal people carry and do. As a filipino martial artist this is especially true, we're knife fans and collect knives but it's it's important to remember that should you ever actually use a blade for self defense you'll want to blend in. A $300s''s specialty blade will look out of place, and while you may be legally defending your life the tides can easily turn, a trained victim can quickly become an assassin (which is illegal). If you ever kill with a weapon you want to blend in and look like a regular guy who found himself in unfortunate circumstances and came out on top. You want the jury to identify with you. If you're painted as an experienced martial artist killing machine you have less chance of escaping jail time. A specialty blade or anything that looks intimidating for the situation it was used can be used against you. The OPs example isn't too extreme but still doesn't fit in your average suburban setting unless you have good reason for carrying such a blade (hunting trip, recent camping, fishing tackle accessory). As a martial artist if you're trained to protect your life you should understand the realities of what might happen if you survive a deadly altercation. If your group portrays a "deadly" persona or uses "deadly" tactics as a marketing tool, it can be used against you if you ever defend your life at the expense of a criminal's. The "deadly" image might attract students and take in the $ but it actually might do a disservice to those that actually need the art.



My Kali instructor, GM Tuan taught defensive tactics to the San Francisco LE. He said a daily self defense blade need be no more than 4". He preferred a pocket carry knife. In Kali most of the blade attacks are slicing attacks, seldom stabbing. Per GMTuan who also has a law degree, from a legal perspective, being able to prove your knife attacks are/were not stabbing actions helps the legal battle ahead. Helps define intent as SD and not taking a life. 
I loved the idea that most Kali moves are offense & defense in the same motion(s). 
Growing up in the southeast it still isn't unusual to see a knife sheathed on someone's side but that doesn't seem to be the etiquette in larger population areas.


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## dvcochran

To reduce my ignorance, what does EDC stand for? Is there a difference between a combat knife and a survival knife?


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## Danny T

dvcochran said:


> To reduce my ignorance, what does EDC stand for?


EDC...'Every Day Carry'



dvcochran said:


> Is there a difference between a combat knife and a survival knife?


Yes, though either can be utilized in either situation. 
Some differences is in having a finger choil and a guard on the different knives.
Many combat knives don't use a sharpening choil which makes sharpening next to the ricasso a bit more difficult but prevent the blade from being caught in clothing when thrust in completely whereas others do use a choil.

Tactical knives again though can be used in combat situations are not designed as a combat knife. They tend to be lighter and a bit more ergonomic and with different features for urban use vs a survival or combat knife.


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## Runs With Fire

drop bear said:


> .


Drill a hole in the handle for a lanyard.  I like my MORAKNIV Companion Heavy Duty, in carbon steel cause I'm old fashoined.


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## Billy02

Gerber also has some good combat knives, you should have a look at them.


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## Bino TWT

My idea of a good combat knife lol


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## Deafdude#5

Everyone is different. 
Define your standards for combat/self defense/utility & choose accordingly.


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## drop bear

Billy02 said:


> Gerber also has some good combat knives, you should have a look at them.


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## Bino TWT

Malos1979 said:


> Kerambit you mean, also a hype.
> 
> And most people don't even recieve proper training for this.



Yes, this is a Karambit, my preferred blade of choice, and I am trained to use it. Like I said, my idea of a good combat knife, a great EDC. This is not hype, however. I personally designed and made this particular Karambit for GM Rene Latosa.


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## CB Jones

Esee Knives - Junglas II


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## Deafdude#5

That’s a big ole knife!!! It’s a handsome knife, very nice.

Not something I could carry with me everyday.
Plus, I get very nervous drop that much cash on something like that.

To me, knives are tools. If I had to use one in self defense. Chances are that it would be seized as evidence by the police until all things were sorted out. I prefer something a little less costly and conspicuous.


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## CB Jones

Deafdude#5 said:


> That’s a big ole knife!!! It’s a handsome knife, very nice.
> 
> Not something I could carry with me everyday.
> Plus, I get very nervous drop that much cash on something like that.
> 
> To me, knives are tools. If I had to use one in self defense. Chances are that it would be seized as evidence by the police until all things were sorted out. I prefer something a little less costly and conspicuous.



We give those knives to guys when they promote or transfer out of the unit (in good standing).  The badge and the years in the unit are laser etched on the other side.

But they are great knives and feel great in your hand.


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## drop bear

dvcochran said:


> To reduce my ignorance, what does EDC stand for? Is there a difference between a combat knife and a survival knife?


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## tim po

realg7 said:


> Sent from my SAMSUNG-SM-G935A using Tapatalk


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## tim po

realg7 said:


> Sent from my SAMSUNG-SM-G935A using Tapatalk


this is not a combat knife. i would classify it as an EDC knife, every day carry. functional for 1000 random cutting tasks, opening boxes, whatever, and no one is going to question any reasonable answer as to why you were carrying it, which makes it a good choice for defense. you are not likely going to win a 'knife fight' with this, and certainly not going to frighten anyone away, but it can be concealed where it can be drawn easily and quietly with either hand and most any position, and has all the edge you need to open arteries or sever tendons and muscle tissue. this is a good knife, my most common EDC is very similar, and the loop for your finger is a good feature.

a combat knife is a knife that is designed for one purpose only-killing men, quickly and efficiently. and no civilian, anywhere that is a populated area, has any business ever carrying a combat knife. if you are hunting elk in grizzly country, whatever, good luck! but you will never get away with using one for self-defense because you cannot justify carrying one.

if you want to understand what makes a combat knife what it is, and not a hunting knife, or a bushcraft knife,  the handle, not the blade is the key. the blade will be long enough to reach the internal organs, feature a drop point and blood groove for penetrating power, and lack any kind of ridgeback notching saw or seration, which will slow it down on the way back out. but the handle will have three main features:
1 .a rounded handle that is natural to hold with a firm thumb-over grip
2. a finger guard. this is not to protect your fingers from your enemies blade, when you are swashbuckling like in movie knife fights. it is there to protect your fingers from your own blade. the handle will be slippery, once it is covered in blood.
3. a flat pommel. many sooped-up aggressive tactical knives have a spike or something on the pommel end. the reason a combat knife has a flat pommel is so you can smack it with the palm of your other hand to push it through a ribcage, without injuring your hand.


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## isshinryuronin

dvcochran said:


> Growing up in the southeast it still isn't unusual to see a knife sheathed on someone's side but that doesn't seem to be the etiquette in larger population areas.


Guns, knives, Jon boats and pickup trucks.  The sound of rifle fire in the morning.  Respect for the land, and a willingness to lend a hand.  Hard to tell the rich from poor.  As a Yankee living in the wooded hill country of upstate SC, I saw another side of the great USA.


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## frank raud

tim po said:


> if you want to understand what makes a combat knife what it is, and not a hunting knife, or a bushcraft knife, the handle, not the blade is the key. the blade will be long enough to reach the internal organs, feature a drop point and blood groove for penetrating power, and lack any kind of ridgeback notching saw or seration, which will slow it down on the way back out. but the handle will have three main features:
> 1 .a rounded handle that is natural to hold with a firm thumb-over grip
> 2. a finger guard. this is not to protect your fingers from your enemies blade, when you are swashbuckling like in movie knife fights. it is there to protect your fingers from your own blade. the handle will be slippery, once it is covered in blood.
> 3. a flat pommel. many sooped-up aggressive tactical knives have a spike or something on the pommel end. the reason a combat knife has a flat pommel is so you can smack it with the palm of your other hand to push it through a ribcage, without injuring your hand.


Based on your stated requirements for a combat knife, please explain why the Fairbairn Sykes, the Applegate-Fairbairn, the V-42 knife and the Gerber Mark II are not combat knives. Even the Randall Model 1 doesn't fit all your requirements. Also how does a "blood groove" aid in penetrating power?


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## tim po

frank raud said:


> Based on your stated requirements for a combat knife, please explain why the Fairbairn Sykes, the Applegate-Fairbairn, the V-42 knife and the Gerber Mark II are not combat knives. Even the Randall Model 1 doesn't fit all your requirements. Also how does a "blood groove" aid in penetrating power?


daggers are combat knives, and were popular in medieval times. a dagger does not need a blood groove because two bladed edges are slicing open the hole made by the point so there is no friction. but a dagger is not as versatile as say, a Ka-bar fighting knife, which was designed for the USMC 80 years ago and still is used by armed forces today, and the design has not changed much. a blood groove allows blood and fluids to exit the wound immediately. otherwise the wound does not bleed until the knife is removed, and you will not have an easy time pulling an ungrooved blade out of a body because of the suction created. in a combat knife fight speed is the key to survival, there are more enemies right behind him. you need to make 2,3,4,5 holes very quickly before blood loss will weaken him enough so you can move on to the next one. a serrated blade, like the gerber toy you mentioned, will only slow you down when those useless serrations get hung up in the layers of fascia and viscera that you push it through, not to mention the ripstop kevlar tactical vest that your enemy is wearing, if we're talking war, not street thug. 
there is little difference between a hunting knife and a combat knife, the former also being intended for killing a large mammal, but there is a difference in finishing off a gut-shot deer, and pick-sticking to the death with another human. don't be fooled by 'cool' looking knives. a combat knife is a boring knife to look at. the cool ones are toys.


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## frank raud

tim po said:


> daggers are combat knives, and were popular in medieval times. a dagger does not need a blood groove because two bladed edges are slicing open the hole made by the point so there is no friction. but a dagger is not as versatile as say, a Ka-bar fighting knife, which was designed for the USMC 80 years ago and still is used by armed forces today, and the design has not changed much. a blood groove allows blood and fluids to exit the wound immediately. otherwise the wound does not bleed until the knife is removed, and you will not have an easy time pulling an ungrooved blade out of a body because of the suction created. in a combat knife fight speed is the key to survival, there are more enemies right behind him. you need to make 2,3,4,5 holes very quickly before blood loss will weaken him enough so you can move on to the next one. a serrated blade, like the gerber toy you mentioned, will only slow you down when those useless serrations get hung up in the layers of fascia and viscera that you push it through, not to mention the ripstop kevlar tactical vest that your enemy is wearing, if we're talking war, not street thug.
> there is little difference between a hunting knife and a combat knife, the former also being intended for killing a large mammal, but there is a difference in finishing off a gut-a combat knifeshot deer, and pick-sticking to the death with another human. don't be fooled by 'cool' looking knives. a combat knife is a boring knife to look at. the cool ones are toys.


So a knife that doesn't fit your description can be a combat knife. And a multi- purpose knife, like a Kabar can be a combat knife. I did ask you to explain how a " blood groove" aids in penetration, near as I can tell you gave an explanation of how it aids in removing a blade from a body. By the way, was the Gerber a " toy" before they added the serrations?


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## Flying Crane

Here is a bit of information on the “blood groove”.









						The Blood Groove
					

Update – 9 June 2020 – a commenter has pointed out that the ‘Marine Corps Dictionary’ that I originally referenced may not have been a ‘thing’ and that the USMC …




					bshistorian.wordpress.com
				




The notion of the blood groove (the proper term is actually “fuller”) has nothing to do with suction or the flow of blood.


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## frank raud

Flying Crane said:


> Here is a bit of information on the “blood groove”.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> The Blood Groove
> 
> 
> Update – 9 June 2020 – a commenter has pointed out that the ‘Marine Corps Dictionary’ that I originally referenced may not have been a ‘thing’ and that the USMC …
> 
> 
> 
> 
> bshistorian.wordpress.com
> 
> 
> 
> 
> 
> The notion of the blood groove (the proper term is actually “fuller”) has nothing to do with suction or the flow of blood.


Shh, we have an expert knife man here. Don't go pointing out " facts".


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## frank raud

Seriously, the amount of fighting knives from multiple cultures that are outside the extremely limited parameters our boy states is what qualifies " a fighting knife" is staggering.


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## Flying Crane

A knife is simply a tool that can also be used as a weapon, should the need arise.  The luxury of creating an “optimal” design for a fighting knife is, I suspect, the product of a wealthy society with leisure time and resources to spend on such things, and is likely dictated by the materials available and the specific environment in which a person in that environment is likely to find himself in a conflict.  So this can vary tremendously from one era and culture to another.  

So if you were a peasant in Medieval Europe, likely that one knife that you owned that was your tool in the field and around the house, and with which you prepared and ate your meals, was also your fighting knife, and was probably the same knife used by your great grandfather and will be used by your great grandson.  Because peasants didn’t have the wealth and freedom to buy and collect new knives like we do today, so they made a tool last until it was broken or lost or otherwise ruined.  

Kinda like their wood-cutting axe.  If need be, it also served as a weapon.


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## drop bear

Flying Crane said:


> A knife is simply a tool that can also be used as a weapon, should the need arise.  The luxury of creating an “optimal” design for a fighting knife is, I suspect, the product of a wealthy society with leisure time and resources to spend on such things, and is likely dictated by the materials available and the specific environment in which a person in that environment is likely to find himself in a conflict.  So this can vary tremendously from one era and culture to another.
> 
> So if you were a peasant in Medieval Europe, likely that one knife that you owned that was your tool in the field and around the house, and with which you prepared and ate your meals, was also your fighting knife, and was probably the same knife used by your great grandfather and will be used by your great grandson.  Because peasants didn’t have the wealth and freedom to buy and collect new knives like we do today, so they made a tool last until it was broken or lost or otherwise ruined.
> 
> Kinda like their wood-cutting axe.  If need be, it also served as a weapon.



The bollock knife and the dirk were dedicated fighters.

But probably a bit later than medieval peasant times.









						Bollock dagger - Wikipedia
					






					en.m.wikipedia.org
				




Not sure about the seax.


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## tim po

. he asked about 'combat knives', not fighting knives. specific parameters. 

I may be misinformed about the 'blood groove' or 'fuller' if that is what it is called. but i will need to read something posted on a site not caller THE BS historian.

The article also did point out something that is very true, most knives for sale to the public today were designed and manufactured for really only one purpose: appeal to the consumer. a knife maker wants to sell knives, not make them. the simpler the knife is usually the better fighting tool.

V-42 knives are legit. and the only missing feature on most of them is a flat pommel, but a thin dagger has extreme penetrating power. but it is not as efficient for slashing. they also do not benefit from a channel, whatever the reason is.


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## Flying Crane

tim po said:


> . he asked about 'combat knives', not fighting knives. specific parameters.
> 
> I may be misinformed about the 'blood groove' or 'fuller' if that is what it is called. but i will need to read something posted on a site not caller THE BS historian.



He is not the only source I’ve seen to discuss this point.  That was simply the first site I found with about 8 seconds of Google-fu.  If you want to see it from another source, I’m sure you could find one within 15 seconds.


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## Dirty Dog

tim po said:


> I may be misinformed about the 'blood groove' or 'fuller' if that is what it is called. but i will need to read something posted on a site not caller THE BS historian.


There's no "may" about it. You're wrong. It's a common enough misconception, but wrong none-the-less.


tim po said:


> V-42 knives are legit. and the only missing feature on most of them is a flat pommel, but a thin dagger has extreme penetrating power. but it is not as efficient for slashing. they also do not benefit from a channel, whatever the reason is.


The fuller makes a blade lighter, stronger and more rigid. 
The notion that a thin dagger has some magical penetration property is nonsense.


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## tim po

i stand corrected, the fuller is just as you say. 
i still say that blade shape has everything to do with penetration ability.


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## Flying Crane

Dirty Dog said:


> There's no "may" about it. You're wrong. It's a common enough misconception, but wrong none-the-less.
> 
> The fuller makes a blade lighter, stronger and more rigid.
> The notion that a thin dagger has some magical penetration property is nonsense.


I’m not sure that a fuller actually makes it stronger.  It does make it lighter, and if done properly should not weaken the blade, at least not significantly.  But I’m not sure it actually makes it stronger.  I’ll need to look into that one.


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## tim po

tim po said:


> you're aggressive, for a worn out tired old fat man. maybe you should be gentle with me.  the shape of a blade most definitely affects it's ability to penetrate, i don't know much about magical blades, but maybe you could tell us about them?. or just pick out what i said that was incorrect so you can belittle me and bury all that i said that is true, does that make you feel cooler? i was not responding to you, you don't seem to be here to learn, but to teach. so, respond to the poster, answer his question with your wisdom. we can agree to disagree.





Flying Crane said:


> I’m not sure that a fuller actually makes it stronger.  It does make it lighter, and if done properly should not weaken the blade, at least not significantly.  But I’m not sure it actually makes it stronger.  I’ll need to look into that one.


it makes sense, the concavity would increase rigidity, and would help keep a long blade straight. and weight affects balance.

and btw i tried to edit the above comment in favor of the second one, and I regret reacting that way.


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## tim po

tim po said:


> it makes sense, the concavity would increase rigidity, and would help keep a long blade straight. and weight affects balance.
> 
> and btw i tried to edit the above comment in favor of the second one, and I regret reacting that way.


and it wasn't directed at you, i was quoting his avatar


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## Flying Crane

I checked a source on fullers, Jim Hrisouolas, one of his books on blade making.  He simply states that it lightens the blade for the width without compromising strength.  Nothing about making it stronger.  I am not sure that I would buy the notion that it make it stiffer either.  If anything, my intuition says it would make it more flexible.  I am thinking more on the terms of a sword blade, than a knife.


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## dvcochran

tim po said:


> it makes sense, the concavity would increase rigidity, and would help keep a long blade straight. and weight affects balance.
> 
> and btw i tried to edit the above comment in favor of the second one, and I regret reacting that way.


That would depend on how the blade is made. If it is forged to a concave shape then yes, it would increase rigidity (assuming it is tempered). 
If it is machined or stamped to a concave shape, then it will have the same rigidness qualities of the metal it was fabricated from. You have to change the molecular properties to affect the modulus of rigidity. 

Modulus of rigidity formula: G = τ/γ and G = E/(2(1+v)). 

It is a tough one to understand.


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## lklawson

Flying Crane said:


> I checked a source on fullers, Jim Hrisouolas, one of his books on blade making.  He simply states that it lightens the blade for the width without compromising strength.  Nothing about making it stronger.  I am not sure that I would buy the notion that it make it stiffer either.  If anything, my intuition says it would make it more flexible.  I am thinking more on the terms of a sword blade, than a knife.


A fuller makes a blade "stronger" for the same weight and space dimensions, giving it greater rigidity and shear resistance, and works in exactly the same principle that an I-Beam does.  It's simple mechanical engineering.

In short, a fuller is the blade equivalent of an I-Beam.

Peace favor your sword,
Kirk


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## lklawson

dvcochran said:


> That would depend on how the blade is made. If it is forged to a concave shape then yes, it would increase rigidity (assuming it is tempered).
> If it is machined or stamped to a concave shape, then it will have the same rigidness qualities of the metal it was fabricated from. You have to change the molecular properties to affect the modulus of rigidity.
> 
> Modulus of rigidity formula: G = τ/γ and G = E/(2(1+v)).
> 
> It is a tough one to understand.


Fullers obey the Beam Equation.  The modulus of rigidity is important for the material but you can't apply it in isolation to an I-Beam.

Peace favor your sword,
Kirk


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## Flying Crane

lklawson said:


> A fuller makes a blade "stronger" for the same weight and space dimensions, giving it greater rigidity and shear resistance, and works in exactly the same principle that an I-Beam does.  It's simple mechanical engineering.
> 
> In short, a fuller is the blade equivalent of an I-Beam.
> 
> Peace favor your sword,
> Kirk


Yes, that is understood.  But I think the key portion that often may not be recognized by most people is the qualifier: for the same weight and dimensions.  So if you take two blades of identical thickness, shape, taper, and distal taper; in short, two blades that are identical, but with the difference that one blade has a flattened diamond cross-section, and the other has a fuller for some significant portion of the length of the blade, I believe the flattened diamond will be stronger and stiffer.  However, the trade-off is that it will be heavier and less maneuverable.

In order to compare two blades of equal mass, one with a fuller and one without, you need to change the dimensions of the blade.  If length and base thickness are equal, then the fullered blade will be wider than the non-fullered blade.  So no matter how you compare them, there is something about them that is not equal.  Either width is different or thickness is different or mass is different.  They cannot have equal dimensions (shape) in all respects, if mass is the same, when one has a fuller and the other does not.

Another way to look at it:  if you took a square beam with certain width and depth, and you compared it with an I-beam that had the same outer measurements, the square beam is definitely stronger, but also much much heavier.  If you took the material from that square beam and turned it into an I-beam of the same length, the width and depth measurements would be much larger, your I-beam would be much larger in those dimensions.  

So in making a sword blade (I know, we are moving away from the knife discussion) you can use the same amount of material to make a wider blade (better for cutting) while maintaining good strength and rigidity, and not making it heavier for the extra width. 

But if you make a sword blade without a fuller, and then cut a fuller into it and remove some steel and make the blade lighter, you do not increase the strength and stiffness in doing so.  What you have done is lighten the blade which makes it more maneuverable, and the resulting cross-section remains structurally sound with good strength and good stiffness.  But not more strength and stiffness than it had before the fuller was cut into it.


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## dvcochran

lklawson said:


> Fullers obey the Beam Equation.  The modulus of rigidity is important for the material but you can't apply it in isolation to an I-Beam.
> 
> Peace favor your sword,
> Kirk


True, but there no major span to consider in a carry length blade.


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## Dirty Dog

tim po said:


> i stand corrected, the fuller is just as you say.
> i still say that blade shape has everything to do with penetration ability.


You can say it all you like, that won't make it true. I've dealt with a couple knife wounds over the last 40 years in the ER, and the shape of the blade really doesn't matter.


Flying Crane said:


> I’m not sure that a fuller actually makes it stronger.  It does make it lighter, and if done properly should not weaken the blade, at least not significantly.  But I’m not sure it actually makes it stronger.  I’ll need to look into that one.


The fuller removes material (hence lighter) and increases surface area (hence stronger).


Flying Crane said:


> I checked a source on fullers, Jim Hrisouolas, one of his books on blade making.  He simply states that it lightens the blade for the width without compromising strength.  Nothing about making it stronger.  I am not sure that I would buy the notion that it make it stiffer either.  If anything, my intuition says it would make it more flexible.  I am thinking more on the terms of a sword blade, than a knife.


Jim is a great guy. We disagree on a few things though. Depending on a lot of details about overall blade crossection, materials, forging technique and heat treating the fullered blade may not actually be stronger than the un-fullered (in large part because "strong" isn't really clearly defined). Rigidity might be a better word. But if the two blades have identical characteristics, but the fullered blade uses less material (and is thus lighter) then it's stronger.


dvcochran said:


> That would depend on how the blade is made. If it is forged to a concave shape then yes, it would increase rigidity (assuming it is tempered).


Have you ever seen (or even heard rumor of) someone forging a blade and not heat treating it? I'm honestly not sure how that would even be possible.


dvcochran said:


> If it is machined or stamped to a concave shape, then it will have the same rigidness qualities of the metal it was fabricated from.


Same question. Who stamps knives? 
Regardless, the greater surface area of the fullered blade still makes it stronger.


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## Flying Crane

Dirty Dog said:


> Jim is a great guy. We disagree on a few things though. Depending on a lot of details about overall blade crossection, materials, forging technique and heat treating the fullered blade may not actually be stronger than the un-fullered (in large part because "strong" isn't really clearly defined). Rigidity might be a better word. But if the two blades have identical characteristics, but the fullered blade uses less material (and is thus lighter) then it's stronger.


I disagree with your points.  From what I’ve read it’s more about the area of the cross-section.  The I-beam shape, when properly loaded. Is stronger than a square beam with the same area of the cross section.  But the overall dimensions of that I-beam will be much larger than the square beam.  But if we consider the fullered blade as an I-beam and the non fullered blade as the square beam, if the area of the cross section is equal, the shape of the fullered blade becomes significantly wider.  Thus to have a meaningful comparison, we need identical area of the cross section. This changes the overall dimensions of the blades significantly.

As I stated, if you make a blade, then cut a fuller into it, you reduce the area of the cross section and it becomes less strong.  You have made it lighter, but not stronger and I am doubtful about stiffer.  The blade is still strong, I am not implying otherwise.  But it does not become stronger by cutting in a fuller.  

Good discussion of the i-beam here:








						What is the difference between an I-section and rectangular beams?
					

Answer (1 of 2): This is an I-Section  Here are some Rectangular Steel Beams:  The most notable difference is that the rectangular beam has two vertical sides, while the I section has one vertical web. The I-Section is a more efficient use of the material due to its greater Fourth Moment of Inertia.




					www.quora.com


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## dvcochran

Dirty Dog said:


> Have you ever seen (or even heard rumor of) someone forging a blade and not heat treating it? I'm honestly not sure how that would even be possible.


Sure it would. Forging is heating a metal to the point it is malleable. Tempering/heat treating is taking it considerably beyond this temperature to change the molecular properties of the metal. Usually done in subsequent heating/cooling stages. This is how properties like hardness are made different. 
When you work the hoofs on cattle you want the blade soft so we have made several drawing blades, none of them heat treated.


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## Dirty Dog

dvcochran said:


> Sure it would. Forging is heating a metal to the point it is malleable. Tempering/heat treating is taking it considerably beyond this temperature to change the molecular properties of the metal. Usually done in subsequent heating/cooling stages. This is how properties like hardness are made different.
> When you work the hoofs on cattle you want the blade soft so we have made several drawing blades, none of them heat treated.


You're not using the terms the same way as a blade maker. And your statement that heat treating is done at a higher temp than forging is just plain wrong.
Depending on the material, forging is done from 900F to 2000F. Most mild steel (probably the most commonly used blade steel) is between 1100F and 1300F.
Tempering and annealing is between 400F and 800F, with that same mild steel example being 400-700F.
Quenching a blade when it's too hot is a good way to start a new blade. After the first one breaks.
It's not really possible to forge a blade without heat treating to at least some extent. Say you heat it hot enough to forge, pound on it, and then set it aside to cool. That's essentially annealing. It's going to be a crappy heat treat, but a heat treat none the less. What you should be doing is forging the blade, then heating and quenching it, and then heating it and allowing it to cool slowly. You can get whatever degree of hardness you like in doing so. Is that worth it for a hoof knife, or just pound it and go with the crap heat treat? Up to you.


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## dvcochran

Dirty Dog said:


> You're not using the terms the same way as a blade maker. And your statement that heat treating is done at a higher temp than forging is just plain wrong.
> Depending on the material, forging is done from 900F to 2000F. Most mild steel (probably the most commonly used blade steel) is between 1100F and 1300F.
> Tempering and annealing is between 400F and 800F, with that same mild steel example being 400-700F.
> Quenching a blade when it's too hot is a good way to start a new blade. After the first one breaks.
> It's not really possible to forge a blade without heat treating to at least some extent. Say you heat it hot enough to forge, pound on it, and then set it aside to cool. That's essentially annealing. It's going to be a crappy heat treat, but a heat treat none the less. What you should be doing is forging the blade, then heating and quenching it, and then heating it and allowing it to cool slowly. You can get whatever degree of hardness you like in doing so. Is that worth it for a hoof knife, or just pound it and go with the crap heat treat? Up to you.


Had to go back and look. I do have the heat treat temps backwards. Heat treat about 400-800 F. Forging about 1600-2200 F. 
This is for 4140 or common tool steel. The number will vary depending on the metal. 
I have never seen steel treated at 400 so I have no clue what that would do since 4140 is stable at 325. It would take a Long time. 

Have you ever worked an animals hoof?  They bleed very easy when trimming or dealing with a callous or ulcer.  A soft blade goes a long way.


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## Dirty Dog

dvcochran said:


> Had to go back and look. I do have the heat treat temps backwards. Heat treat about 400-800 F. Forging about 1600-2200 F.
> This is for 4140 or common tool steel. The number will vary depending on the metal.
> I have never seen steel treated at 400 so I have no clue what that would do since 4140 is stable at 325. It would take a Long time.


It is. I do mine by sticking them in an old oven. A couple hours at heat, then cool slowly. I generally leave them in overnight. 
Another fellow I know swears by heating them with a torch and then burying them in sand. We all have our preferences. Like, I prefer canola oil to water for quenching. I don't think it actually changes the heat treat significantly, but it makes the shop (one bay of our garage...) smell like someone baked cookies.


dvcochran said:


> Have you ever worked an animals hoof?  They bleed very easy when trimming or dealing with a callous or ulcer.  A soft blade goes a long way.


I have not. What is the advantage of a soft blade?


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## lklawson

Dirty Dog said:


> It is. I do mine by sticking them in an old oven. A couple hours at heat, then cool slowly. I generally leave them in overnight.
> Another fellow I know swears by heating them with a torch and then burying them in sand. We all have our preferences. Like, I prefer canola oil to water for quenching. I don't think it actually changes the heat treat significantly, but it makes the shop (one bay of our garage...) smell like someone baked cookies.


I haven't heard of anyone that quenches with water. Hardens the blade too much and induces stress. I'm not sure even a decent tempering could take it out. Is there something that I'm missing? Some sort of steel that likes to be water quenched?

Peace favor your sword (mobile)


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## Dirty Dog

lklawson said:


> I haven't heard of anyone that quenches with water. Hardens the blade too much and induces stress. I'm not sure even a decent tempering could take it out. Is there something that I'm missing? Some sort of steel that likes to be water quenched?


The W steels are often water quenched. I understand some people even quench things like 1095 in water, but I don't think it's very common. The blades tend to be too hard and brittle. The people I know who use water heat it before the quench.


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## dvcochran

Dirty Dog said:


> It is. I do mine by sticking them in an old oven. A couple hours at heat, then cool slowly. I generally leave them in overnight.
> Another fellow I know swears by heating them with a torch and then burying them in sand. We all have our preferences. Like, I prefer canola oil to water for quenching. I don't think it actually changes the heat treat significantly, but it makes the shop (one bay of our garage...) smell like someone baked cookies.
> 
> I have not. What is the advantage of a soft blade?


You can still make a soft blade sharp but of course it will not stay that way very long. Being soft it is easier to feel when you hit something (like the quick) that you do not want to cut. The two-handed draws you can purchase are made this way. 
I am sure if I was a Vet and doing it every day it would not matter as much.


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## dvcochran

lklawson said:


> I haven't heard of anyone that quenches with water. Hardens the blade too much and induces stress. I'm not sure even a decent tempering could take it out. Is there something that I'm missing? Some sort of steel that likes to be water quenched?
> 
> Peace favor your sword (mobile)


I have seen quite a lot of large quenching processes that use water with the temp just below boiling. These are cast aluminum or iron parts most often, but I have seen welded steel parts quenched to remove stresses. 
These are machines the 1/2 the length of a football field. They bring the parts up to heat for something like 8 hours, then quench, then hold them for another 8 hours at a lower temp. Going from memory the temps are like 900 pre-quench and 500 post-quench.


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## lklawson

dvcochran said:


> I have seen quite a lot of large quenching processes that use water with the temp just below boiling. These are cast aluminum or iron parts most often, but I have seen welded steel parts quenched to remove stresses.
> These are machines the 1/2 the length of a football field. They bring the parts up to heat for something like 8 hours, then quench, then hold them for another 8 hours at a lower temp. Going from memory the temps are like 900 pre-quench and 500 post-quench.


That's cool but not really what I'm interested in.  Quenching steel without making it brittle and inducing the stress cracks and developing the wrong grain structure.

Most of the time, water quenching steel makes it hard but brittle with cracks.  I'm completely unfamiliar with the W branch of steel's resilience to water quenching so I find it fascinating.  Prior to this, everyone I know quenches with oil (both petroleum and vegetable), often pre-heated oil.    It seems that I have some more reading to do now.  

Peace favor your sword,
Kirk


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