View Full Version : The Katana and Piercing/ Cutting Armor

7th December 2003, 18:17
Hi everyone,

I've been talking with those WMA-folks too much lately. I've heard the argument alot that the katana's edge and thickness (I don't remember the technical terms) aren't designed to effectively cut/ pierce armor. Now I know that the katana/tachi WERE weapons of war, and that they were used against opponents in armor.

So my question(s) is: Is it true that the katana's edge/thickness isn't designed as effectively as some European swords? Did the design of the katana/tachi change over time, meaning are modern blades different from blades from the warring-periods?

Also I wanted to ask if this is even a relevant question. I mean, did medival samurai actually worry about striking armor directly? I know that Japanese armor was designed with more openings/ weak points/ whatever than plate armor was. I could see how a samurai might not worry about cutting through armor, instead only aiming for openings in the armor (I've heard some koryu aim for weak spots in Japanese armor). But then again, real combat is a messy thing, and its easy to miss your intended target on a moving opponent.

PS: I know there are misconceptions on both the WMA side and the Eastern side. I'm not trying to start an argument about that, I'm just trying to get some real facts. Also, if there was a previous thread on the topic that I missed I would gladly accept a link.


7th December 2003, 20:47
My understanding is that Japanese swordsmanship takes advantages of weak areas in the armor as opposed to trying to pound straight through it. For that matter, despite the image of proud samurai charging into battle katanas at the ready, battles seem to have been fought and won with the yari (spear) and bow. The tachi/katana was more like a modern soldier's 45 caliber pistol, better than nothing. While some schools of swordsmanship do still practice (occasionally) in armor, most of what we now know as classical kenjutsu went through a major revision from simple battlefield techniques to dueling, the far more likely form of combat. It was during times of relative peace that the katana became the weapon of choice. It's inconvenient to go out carousing with a 12' spear...

WMA practitioners would do better to compare the katana and it's abilities to the rapier rather than the bastard sword. The historical records I have seen show more deaths in battles from rocks, bows and spears than swords. (It is also my understanding that this is likewise true for Western records, where the sword was also given more credit than it was due as a tool of war.)

That said, here's a link (http://www.shinkendo.com/kabuto.html) to Obata Sensei's kabutowari demonstration. It shows rather clearly that in the right hands, the katana could in fact do more than a little bit of damage directly to armor.

Thanks in advance for any and all clarifications and corrections to the above.

8th December 2003, 00:58
This topic has been banted about on other forums too and I shall leave it to folks more studied than I, but I would like to ask about the link reporting the test cut. Sorry if this is off-topic.

At the top it says the sword used was "a sword created in the ancient Japanese fashion by American swordsmith, Paul Champagne" was used to cut a "authentic 'Hineno' style kabuto, dating back between 1573-1602." Since I couldn't find my answers on the site, perhaps someone here familiar with said test can help me.

The sword - It says it was made in the ancient fashion which I take to mean traditional forging techniques. Does this mean steel of traditional quality was also used? I have heard that the poor quality iron sand used by many smiths was made up for by the master work of the craftsman, but I have also heard that modern metallurgy and materials yeild better average quality blades than the average blades of old.

Is the blade made by Mr. Champagne of equal, less, or greater metallurgical composition than a historical weapon from the same period as the helmet?

Which brings me to my next questions -

Is the helmet as strong as the day it was made? Shouldn't the helmet also be modern-made to make it a true test (to make it similar in composition with the sword and allow for the ravages of time)?

If the almost 400 year old helmet is as strong today as it was back then, I would say the test has fewer possible problems with it, provided the sword is compositionally similar (not simply made in the ancient fashion but with better materials) as well.

I don't mean to attack the authors of the site or practitioners of the art, I'm simply curious about the test cutting. I'm sure there are flaws in my logic... it is Monday afterall. Thank you!

8th December 2003, 15:18
You might address your questions to Nathan Scott, a long time student of Obata Sensei's. He would be the best resource I know of for more information about this demonstration.

I agree with your strain of logic, but after handling a number of kabuto from that time period, am still in awe of putting that big of a gash in a kabuto. Based on Obata Sensei's reputation, I would imagine he chose a kabuto that was in good repair. Good questions, but I still think the demonstration is a good representation of the *potential* damage that can be done with a katana on armor.

Earl Hartman
8th December 2003, 20:15
Most katana that people see today have what is called an "art polish", the purpose of which is to bring out the visual qualities of the blade so they can be enjoyed by the collector. That is, the purpose of such a polish is aesthetic, not practical. Such a polish gives the sword a thin, razor-sharp edge. In addition to that, collectors (most of whom have no idea about how to actually use a sword and who treat it solely as an art object rather than a weapon) take exquisite care with their blades, since any imperfection, no matter how small, is extremely costly to repair and can significantly reduce the market value of their blades. As a consqequence, they give the impression that a katana is a delicate thing that can be easily damaged.

People like Hyaku, Nathan, and Dan Harden can address this issue more fully, but AFAIK swords used in actual fighting were polished differently and were given a completely different edge geometry, one that would be more robust and which would allow the sword to take more punishment without being severely damaged. Also,as I understand it, the edge geometry suited for cutting soft targets like straw matting, which is the use to which most modern swords are put if they are not in the hands of collectors, is not suited for cutting armor.

Nathan Scott
8th December 2003, 20:27

The kabuto was in fact in very good shape, and was not rusted out or weakened by any means. It was chosen for its condition, and because as far as antiques go, this type of kabuto is fairly common. Helmets such as this would have been commonly encountered on the battlefield.

As many of you may know, the kabuto (helm) is the hardest part of Japanese armor, mainly because it is built around an iron "bowl". These bowls are often reused in later period helms.

The test was a one time experiment based on historical testing practices (weapon vs. armor) performed by qualified sword testers.

As far as using a new replica kabuto goes, that was of course considered. But there would be twice as much controversy about whether a modern reproduction would be equal to the historical helms. The only way to get around this type of criticism was to split an actual antique. Steel does not just "go bad", so I think this type of logic is a little humerous. FWIW, Obata Kaiso still has the kabuto, and I've seen it numerous times myself. There are photos posted of it as well.

Obata Kaiso had done a bit of consulting as a sword tester for Paul Champagne, and it was he who requested that his blade be tested in such a fashion. That is the reason his blade was used for the test - it was not performed as a test/demonstration of swordsmanship skill, though of course this is a by-product of such a test.

I don't know whether a Paul Champagne sword is stronger or weaker than your "average" historical nihonto. I do know that the sword Paul made was forged of modern steel though. Technically, modern swordsmiths have an advantage over past swordsmiths. However, that is not to say that "modern blades are stronger than older blades". Ability and experience is more of a factor in the making of a good blade than technological advancements.

Kabutowari has been performed for hundreds of years using nihonto. While I don't think the average gendai nihonto would survive such a test today, I do believe that similar results are possible from traditional Japanese smithing and tamahagane.

Obata Kaiso expects to be publishing a book on tameshigiri sometime in 2004 (it's in the final stages). I think this book will provide further insight into this subject for those interested.

As far as Western blades being superior for cutting armor than Japanese blades, I suppose that would depend on what period of Japanese sword we are talking about. But my basic suspician is that this is not accurate. The nihonto is VERY efficiently designed to afford maximum cutting/splitting potential, maximum dispersion of shock-force, and very reasonable weight and balance characteristics. Most Western blades I've seen are better suited for thrusting to slashing. But if others disagree, I won't loose any sleep over it! ;)

BTW, this may be nitpicking, but you can't "cut" armor. It would probably clarify the issue better if we substituted cleave or split instead, since this is what happens to harder targets such as armor.


Nathan Scott
8th December 2003, 20:39
Hi Earl,

Good to hear from you. I basically agree with your post, but would add that there was not just one-type of edge/blade geometry that was used in Japanese edged weapons. As the fighting methods changed, the armor changed. As the armor/protective gear changed, the weapons changed. As the weapons changed, the armor changed, etc.

As an example, (as you know) the Edo-jidai was more-or-less 400 years of peace, in which swords were worn as symbols of status, and when used, usually weren't applied against armored opponents. Thus, swords became lighter and shorter for every day wear (and more decorated in many cases), and the edge profiles favored a more narrow shape better suited for cutting "soft targets".


Dan Harden
8th December 2003, 20:40
I have written on this extensively but I cannot find the links here. One is in the stainless steel thread, the other is in an edge geometry thread. I have asked John Lindsey to post them in the archives several times-to no avail. The question continues to be raised as it a VERY good question.
By the way, Earl is down playing his own knowledge on this compelling argument. We have had some excellent exchanges on a topic that we fundamentally agree on.
The edge geometry for earlier Katana’s is not flat on the sides from the Shinogi to the edge. It was a tapering slope (niku or meat in Japanese). As this profile is difficult to polish-as the years went on the niku was polished down as the sword became "tired." Truth be told this geometry was/is found on weapons indigenous to many, many cultures. The reason? It afforded more “metal” to support the edges. Those edges were not razor sharp. A razor sharp edge is a fools errand on weapons of war. A sharp edge capable of sustaining itself on impact blows will cut just fine.
A natural corollary would be animals claws. People routinely call the wounds inflicted by animals claws as the result of "razor sharp" claws-naturally this is ridiculous. The wounds are profound due to force and soft tissues tendency to tear or expand on cutting...impact. No animals claws are that sharp. Do not underplay placticity and fluid dynamics in cutting impact.
If you cut grass rolls, soft metal, trees and then beef or pig with bone with various edge geometry you will learn quite a lot about historians and collectors imaginings about a subject they know little about.

Edge types
In the fullness of time mass production produced hollow ground edges (easier to do on various wheels (water driven or mechanical). Even earlier knives in the industrial age were produced with convex edges (canard, or appleseed being other names) Several makers made a name cutting nails and such with these edges (Buck knives being one of them) As time wore on they switched to convex to meet the demands of successful marketing NOT BETTER KNIVES.

Cutting competitions
Different edges and more importantly; materials- react differently on impact. An ideal edge geometry for cutting grass rolls would be a machete.
A 14" Kukri swung single handed by an experienced person will equal or outcut a 30" Katana
The general idea is to try to duplicate the conditions of any cultures indeginous weapons of war- not make the best grass cutter to win with.

The Japanese myth
For what its worth, every time you read “The Japanese sword is considered the best cutting weapon ever created” in many written sources materials, ask yourself-“By whom?”
No one that I know of with smithing and or extensive weapons experience holds that to be true.


Dan Harden
8th December 2003, 21:07
In the above post I wish to correct the following (simple mistake)

Edge types
In the fullness of time mass production produced hollow ground edges (easier to do on various wheels (water driven or mechanical). Even earlier knives in the industrial age were produced with convex edges (canard, or appleseed being other names) Several makers made a name cutting nails and such with these edges (Buck knives being one of them) As time wore on they switched to concave edges (ground on machines or belts) to meet the demands of successful marketing NOT BETTER KNIVES.

Sorry for the haste

8th December 2003, 22:54
As Mr Hartman says its been well talked over.

I just cant see were the confusion comes in here. Its all really simple

Being priviledged to belong to a couple of old ryu and watching a lot more I fail to see the sense in wanting to even bother to try and disable someone in full armour by striking its strongest parts.

Didnt Obata Sensei do that test to examine the extremes of both weapon and cutter?

Normaly cuts are delivered to unprotected areas. Into the neck, up in between the legs, cut off an arm. Thrusts with a curved pointy weapon under the armpits, chin, legs, its a long list. Looking at this pic I can see lots of nice vulnerable spots

Last and most important is. This all should not be confused with Kendo. Kendo shows a representation of samurai armour but the purpose of kendo is to actualy "strike at it" and not between it

Its about the same as comparing Western fencing to looking for an opening and thusting the epee or sabre up and inside the mask.

Hyakutake Colin

8th December 2003, 23:30
Did Japanese armour designs pretty much go unchanged? If so is this the reason the nihonto design stayed relatively unchanged for the last 800 years? Eurpoean weapon designs always seemed to be in a state of flux as fighting men were having to adapt to changes in armour designs. Or did Japanese armour go through an evolution of sorts? Thanks.

Earl Hartman
8th December 2003, 23:43
Just as an aside, I doubt very seriously that such optimum conditions as resting a helmet on a tree stump and then winding up and taking a huge honking swing at it with your feet spread and firmly planted would prevail in a battle.

If a guy took a shot to the head that was strong enough, he might get his brains scrambled or his neck broken, but I doubt really seriously that even the strongest fighter could actually put a katana through a good kabuto (unless it was one of those giant Kage Ryu suckers that Hyaku likes).

Obata sensei may have put a good gash in the kabuto, but the picture makes it obvious that the katana bounced back strongly and would not have split the wearer's head open. A blow that strong would have surely knocked him cold at the very least.

On a related note, I have seen a photograph of a successful kabuto inuki (shooting an arrow through a kabuto) performed by my kyudo teacher's father-in-law, the famous (if you do kyudo) Urakami Sakae, one of the greatest of the modern kyudo masters.

I do not know how strong the bow used was, but the arrow was quite heavy and fitted with an armor piercing point. The kabuto was shot at from a distance of, I believe 7 or 8 ken, or about 15 meters (the distance at which the arrow stops flexing from the inertia of the release and starts flying completely straight).

The arrow cleanly penetrated the helmet completely, piercing through the front and protruding cleanly out the back, completely impaling the kabuto.

Quite impressive.

For helmet piercing, what you really need is a good war hammer. You can punch a hole in 16 gauge cold-rolled steel with a flick of the wrist.

Nathan Scott
9th December 2003, 00:23
Ya'll are correct that kabutowari is about texting extremes, not recreating specific battle conditions. I would think this would be somewhat obvious when looking at Obata Sensei's test! ;)

On the other hand, there were efforts made to make the test "more realistic". For example, some testers used cheating methods to gain fame, such as one who used a huge blade that looked more like a naginata blade, and another who jumped off a ladder down onto the helmet. Doing things like this is kind of like cutting improperly prepared makiwara (over soaked) and then thinking that you are cutting the same thing other kenshi are cutting. BTW, it's funny that nobody ever questions the type of swords, materials or preparation of tatami/goza type targets shown being cut in numerous demonstrations, online photographs and what not. These factors are critical to understanding what is really being seen.

Anyway, dotangiri (the method used in Obata Sensei's kabutowari) is a sword testing method. Though it is not intended to replicate a combative situation specifically, I do think that it is quite conceivable that such a blow would have been delivered as one type of "todome" (finishing strike). Thrusting is of course a popular type of todome as well, but depending on position and opportunity, percussing the opponent in the right place might be a good way to go.

PS. In the interest of documenting my position on targeting armor, I think it is quite likely that armored/protected targets were attacked on the battlefield. But I know that this point of view is still (currently) in the vast minority. Oh well.

Dan Harden
9th December 2003, 13:51
I think you've tried to explain the validity and purposes for the occasional Helmut cut so many times you should have a flier to send out. ;)

In the interest of documenting my position on targeting armor, I think it is quite likely that armored/protected targets were attacked on the battlefield. But I know that this point of view is still (currently) in the vast minority. Oh well.

Actually I think you'd be surprised at how many would agree to that. Targeting and training is just that-edges intended for soft targets don't always get there and having no other alternative due to positioning or timing but to bash someone you may just due that very thing. While I agree with Earl that war hammers and arrows were just the ticket for puncturing European armor-one need only to strike at plate a few times to witness severe deformation (denting). A dent in a Helmut could kill you. A sharp dent in a chest plate could make it tough to breath or move. There is a reason for padding.
In the occasion or using a sword against Japanese armor; sliding in cuts to lacing or stabing would or could mean _your_ edge also met edges of the forward plating if the targeting was not 100%....scrape...
Example: the armpit cut or stab could encounter suspended wakibiki. A throat stab would work rather nicely sliding up the chest plate under the gorget. But on its way its edges could easily encounter sliding, scraping metal.

All of this is assuming one were encountering a fully armored soldier. And then, if one were using a sword. Yari were nice little tools for stabbing places with. "Reach out an touch someone" had meaning then, as now, although an F15 strike eagle does it better.

So having a razor sharp edge would be a mistake a newbie would probably not repeat. Although I am sure that then as now there were seasoned grunts who taught you how to tie and tuck away your laces and overall how to make a tight package that was good to go.
I would imagine that combat and soldiering and what soldiers do under stress has been a constant throughout culture and time. Budo is a sweet little package of do this and he'll do that, he does this- you do that. But training is only that, soldiering and Murphy go hand in hand.


9th December 2003, 14:20
Originally posted by Dan Harden
...While I agree with Earl that war hammers and arrows were just the ticket for puncturing European armor-one need only to strike at plate a few times to witness severe deformation (denting). A dent in a Helmut could kill you. A sharp dent in a chest plate could make it tough to breath or move. There is a reason for padding.

I watched an interesting show on the History Channel the other night about the Battle at Agincourt (1415). The show I think was called Battlefield Forensics. Anybody else see it? What did you think. They came to the conclusion that the English Longbow was not the reason for the French defeat. They did some testing and decided the Longbow was ineffective against the armour of the time. French advantages were enormous but everything that could have went wrong did. The archers did win the day for England but it wasn’t with their bows but through their melee.

Cady Goldfield
9th December 2003, 15:00
Originally posted by Dan Harden
I have written on this extensively but I cannot find the links here. One is in the stainless steel thread, the other is in an edge geometry thread.

Stainless Steel thread:


Edge Geometry (I think this is the thread Dan is referring to):


10th December 2003, 23:06
The Yagyu-Ryu seminar I attended last year was very informative on battlefield techniques. The swords of that era had a much more curved shape. The Sensei who demonstrated surprised most of us by his techniques (I had no previous knowledge of this style) .

The technique involved reversing the sword with the blade up and thrusting into the groin/armpit area. It was something I was not aware of but makes sense in hindsight.

For my troubles, I used to engage in "Medieval Re-enactment" before I diiscovered MA and have a fair bit of experience in "Fighting" with opponents (purely Re-enactment, not serious!). THe one thing we learnt was you could only rarely strike with an edge - especially where shields or left-hand daggers were involved. Most attacks relied on brute-force bludgeoning, hence the high weight of swords from that period.

BTW These are just my personal observations so they may be picked apart at will by anyone who has better knowledge! (I like to learn new things!).

As for the Longbow thery above - having a bit more experience with them I can say that an English Yew longbow would have little difficulty in piercing Plate armour. I have personally shot an arrow from one through a Car Bonnet (scrap) . This was just a normal arrow and not a Bodkin pointed Armour piercer.

Mat Rous

Jonathan Tow
13th December 2003, 22:57
Just a question to all you historians out there,

There was a comment that Agincourt wasn't won by the longbow but by the melee skills of the English.

As far as I am aware, the English fired volleys of arrows at the French from distance, taking out their horses and making the knights particularly vulnerable on foot. I'm not sure about the weather conditions on that day, but I'm sure that if it was wet, anyone in armour would be struggling in the mud. The English archers didn't wear as much armour and could be a lot more mobile.

Now, is that roughly the historical reason why the English won the day? Or were there other factors?

Feel free to PM or email me if you don't want to wander off topic too much on the thread.



Earl Hartman
14th December 2003, 03:07
IIRC, it went like this at Agincourt:

It had rained all the previous night, and the field was very muddy. The French marched in a tightly packed mass straight up a hill at the English position about a mile away. Many of the knights were wearing especially heavy armor as a defense against the English arrows. Many were knocked off their horses by the English barrage and were trampled into the mud by the host pressing up behind, and many of them drowned. When they got close enough to engage, they were packed so closely that they didn't have sufficient room to maeuver or use their weapons efficiently. The English archers, whose auxilliary weapons were normally a buckler (a small shield) and what was called, I believe, a "Welsh knife" (a kind of short sword) had an easier time in the melee, as their weapons were better suited for close combat.

14th December 2003, 06:50
Yes this was discussed on the Battlefield Detectives program on History Channel and was the major factor. They dug down to find what would have been the top soil at the time of the battle and performed soil testing. The dirt was not normal clay. It created an unusually difficult mire for the french nobles. not just the weight but the metallic surface of the armour caused them to get caught in the mud. the archers were clad in cloth and could didn't get sucked into the mud because the cloth wasn't as slick as the metal armour nor as heavy.

There were other factors:
The practice of ransom inspired greedy French nobles to charge into a bottleneck after the wealthly english nobles and they pretty much ignored the common folk archers who were the real threat. The welsh archers fought very dirty and weren't to impressed with certain high class courtesies. The practice of heraldry was in use to let the enemy know that you were titled and wealthy. If you were wealthy enough they wouldn't kill you they would take you hostage and chage your house ransom. The non-heralded archers just wanted to live. So archer won the the day but it was by melee.

The natural lay of the battlefield compunded the congestion problem. The french had numerical superiority ( around 5 to 1 odds) But they got bottlenecked and couldn't function. The French heavy armour according to the test perform by the reseachers could be penetrate by the longbows but the horses weren't so lucky. A lot of dead horses that day.

It was really interesting program. It was amazing how the French were able to lose that one. One paper they looked like they had over welming odds. Kind of reminds me of the Italians at Beda Fomm. I wish I had recorded the show. They are doing the Alamo this week.