The Science of Samurai Swords

[Johnny Pneumatic]

Does anyone know where I can read about why some samurai swords were made with over a million layers? What effects did having the blade like that do? How easily did Asian swords snap off latterally? I've heard they were quite bad about doing that compared to European swords. Anyone know? Thanks.

[BillC]

The Wikipedia article (http://en.wikipedia.org/wiki/Katana) on Japanese swords should answer some of your questions, particularly the sections on "Myths" and "Comparisons with European swords".

[T'ai Chi]

Originally posted by SkepticJ
Does anyone know where I can read about why some samurai swords were made with over a million layers? What effects did having the blade like that do? How easily did Asian swords snap off latterally? I've heard they were quite bad about doing that compared to European swords. Anyone know? Thanks.

The Chinese straight sword (http://www.martini.nu/justin/jian.jpg) that I have wasn't designed to hack, but rather to cut at soft/vital spots on the body (stomach, wrist, neck, tendon, etc.).

I've heard that if it were to be used to directly strike another sword with a lot of force, like you see in the movies, that it would have probably snapped.

[kedo1981]

The layering on a katana’s blade combines hard and soft steel making the blade sharp and flexible; the layering works like kind of like those Asian noodles where they are folded and doubled each time.

[EdipisReks]

actual katanas are no better than good european blades of the same era. i bet a good fencer with a rapier would kill a samurai fairly easily. speed+reach=dead samurai.

robocop would do even better, unless he was fighting a robot samurai. but then robocop has a jet pack and a big machine gun, so he still wins.

[TeaBag420]

Anyone in this thread who's ever actually used a sword on someone else using a sword please raise your remaining hand.

"I've heard"

"Wikipedia"

Ahh, the giants. (Stark Trek IV).

Jacob bloody Bronowski.... Jesus ****** Christ on a bicycle, do you people not do your research?????

That having been said, you're all looking very lovely today.

[Matabiri]

If you PM me with an e-mail address that can receive a 1.6 Mb pdf, I've got a paper about metal composites, in the context of ancient swords, which may answer some of your questions.

[richardm]

Originally posted by TeaBag420
Jacob bloody Bronowski.... Jesus ****** Christ on a bicycle, do you people not do your research?????


One of the great things about education is that you don't always have to research everything from scratch.

[Filippo Lippi]

Originally posted by kedo1981
The layering on a katana’s blade combines hard and soft steel making the blade sharp and flexible; the layering works like kind of like those Asian noodles where they are folded and doubled each time.

I saw a BBC programme which showed a Saxon sword being forged and this used different pieces of iron with different properties, the effect of the interwoven (?) metals at the end was almost beautiful.

[Matabiri]

Originally posted by Filippo Lippi
I saw a BBC programme which showed a Saxon sword being forged and this used different pieces of iron with different properties, the effect of the interwoven (?) metals at the end was almost beautiful.

Actually; easier than any e-mailing, get the paper here (http://www-stu.cai.cam.ac.uk/~rk237/swords.pdf).

Various pretty pictures, particularly if you're a metallurgist.

[stingy get]

Interesting article here:

http://www.thearma.org/essays/katanavs.htm

[Dr Adequate]

Originally posted by Filippo Lippi
I saw a BBC programme which showed a Saxon sword being forged and this used different pieces of iron with different properties, the effect of the interwoven (?) metals at the end was almost beautiful.
Almost?

It's called pattern welding.

This guy (http://www.anvilfire.com/21centbs/armor/atli/index.htm) can give you the technical details (about halfway down the article).

[Bikewer]

Also the Damascus process. Another aspect of the Japanese technique was in the tempering, which involved layers of clay applied to the blade. Thicker along the sides and back, thinner towards the edge, with the typical "wave" pattern applied by nearly wiping the clay away along the cutting edge.
This, properly done, resulted in a blade with good mechanical strength without being brittle, and a hard cutting edge.

The entire process, (at least by the best makers) was highly ritualized.

This site:
http://swordforum.com/

Has a lot of useful information.

[athon]

Originally posted by Bikewer
Also the Damascus process. Another aspect of the Japanese technique was in the tempering, which involved layers of clay applied to the blade. Thicker along the sides and back, thinner towards the edge, with the typical "wave" pattern applied by nearly wiping the clay away along the cutting edge.
This, properly done, resulted in a blade with good mechanical strength without being brittle, and a hard cutting edge.

The entire process, (at least by the best makers) was highly ritualized.

This site:
http://swordforum.com/

Has a lot of useful information.

I actually own a 14th century Damascan dagger. I bought it in Damascus for a lot of money (always wanted one!) and must say; damn it's pretty.

Athon

[Badly Shaved Monkey]

Originally posted by SkepticJ
Does anyone know where I can read about why some samurai swords were made with over a million layers?

1 million = approx 10²⁰ so it only takes 20 foldings over to make a million layers. However, there can't really be a million layers actually present. If a sword is 1cm thick (for ease of calculation), each layer, if coherently identifiable would be 10^-10m thick, or 1 atom. Given that some irregularity and mixing must occur at each stage I wonnder how many real layers can be produced and if only 100 or 1000 layers can really be demonstrated, is any additional folding just for show or does it have other useful physicochemical effects?

[Matabiri]

Originally posted by Badly Shaved Monkey
I wonnder how many real layers can be produced and if only 100 or 1000 layers can really be demonstrated, is any additional folding just for show or does it have other useful physicochemical effects?

The paper I linked says that swords with ~110 layers have been found, as have swords with ~30. They guessed this was due to repeated folding (had it been perfect, they should have had 128 and 32 layers respectively), and predicted the existance of swords with ~64 layers... one with ~50 layers was duly found.

[T'ai Chi]

Originally posted by TeaBag420
Anyone in this thread who's ever actually used a sword on someone else using a sword please raise your remaining hand.

"I've heard"


Sorry. I never have used my sword on another person, and never plan to. In fact, I will avoid that at all costs.

[Rolfe]

Originally posted by Dr Adequate
Almost?

It's called pattern welding.

This guy (http://www.anvilfire.com/21centbs/armor/atli/index.htm) can give you the technical details (about halfway down the article). I saw that programme too. The pattern on the original sword, though badly corroded, was simply amazing in its regularity and perfection. However, the modern smith who tried to copy the process managed only the equivalent of an average apprentice's first trot round the stable block, in fact without a live master to guide him, possibly not even that good. I think you have to practise for a decade or so to be really good at it.

Makes the forging scene from Siegfried look pretty silly, I have to say.

Rolfe.

[Badly Shaved Monkey]

Originally posted by jzs
Sorry. I never have used my sword on another person, and never plan to. In fact, I will avoid that at all costs.

and will fight to the death anyone who tries to make you? :)

[Xeriar]

Originally posted by kedo1981
The layering on a katana’s blade combines hard and soft steel making the blade sharp and flexible; the layering works like kind of like those Asian noodles where they are folded and doubled each time.

No, the folding was done to remove the impurities from the rather poor iron they had to work with. That effect was caused be dual tempering - cooling the edge of the blade at a different rate than the back.

Sword Forum International hammers out the details. Some blades were folded ten or twenty times but, naturally, they fuse together (if they don't they risk splitting - very bad).

And for the love of all that is holy, don't play with stainless steel blades, I have a video...

http://www.anenris.com/media/unsafesword.mpeg

Stainless steel is hard, yes, and brittle. Honestly I'm surprised the blade seemed to have a full tang.

[Hellbound]

Originally posted by Xeriar
And for the love of all that is holy, don't play with stainless steel blades, I have a video...


I can second this. I have a replica longsword made from industrial spring steel, hand forged. You can hack a cinder block without damaging the blade. You can also lean it on a fence post, stand on the flat of the blade, and it will return to true.

A friend of mine had purchased a stainless stell replica katana, and spent countless hours declaring how much better the katana was, etc, etc, etc. Finally, we had a go at it for a bit. Well, a few good whacks in and the blade of his katana was gone. Stainless Steel does not do well for swords. A brittle blade is a broken blade, when it comes to actual use.

[jj]

Originally posted by TeaBag420
Anyone in this thread who's ever actually used a sword on someone else using a sword please raise your remaining hand.


Do fake ones that the SCA uses count?

[jj]

Originally posted by Matabiri
The paper I linked says that swords with ~110 layers have been found, as have swords with ~30. They guessed this was due to repeated folding (had it been perfect, they should have had 128 and 32 layers respectively), and predicted the existance of swords with ~64 layers... one with ~50 layers was duly found.

I've just got to point out that the claim of 2^n is wrong, wrong, wrong.

Take a piece of metal. Case-harden it, so it's now 3 layers, a thin layer of hard on each side, and a thick layer of soft in the middle.

Now fold it. YOu have FIVE layers. FIVE. The two hard layers that meet in the middle are now ONE hard layer. Case Harden again since you've streched the outside, still 5 layers.

Now, fold. You get NINE layers.

Repeat you get 17.

You should always have an odd number of layers, methinks.

[Xeriar]

Originally posted by jj
Do fake ones that the SCA uses count?

A real blade still feels different than a retan stick. Lighter, even, and often better balanced o_O At least that's my feeling. Opinions and blade quality will vary.

That, and armor will often turn blades better than the SCA rules like to claim.

That said, I've seen demonstrations (my friends wouldn't let me demonstrate with thairs :-). Katanas are very good at searing through flesh - they cut better if you pull back on the blade during your swing (Someone told me this was called 'drawing butter'). The European longsword was also designed to handle armor, the katana less so, though I think there was a version made for this.

[jj]

Originally posted by Huntsman
I can second this. I have a replica longsword made from industrial spring steel, hand forged. You can hack a cinder block without damaging the blade.

My grandfather did something like this, it was a kitchen knife, instead of a sword, and he made it out of an early automotive leaf spring. (He was born in the 19th century, smith then machinist)

I have it. It's indestructable. It sharpens fantastically well. It does NOT hold an edge, it wire-edges like blazes if you don't sharpen it right, but steeled every time you use it, it's a great carving knife, and if you have to chop through the bone, go ahead. THUD.

I've gotten around the wire-edge issue by giving less "thin" taper than modern blades, btw, more like a cleaver bevel. Still very sharp, and quite indestructable.

Also might be the heaviest 12" kitchen knife I've ever used.

[TeaBag420]

Originally posted by Badly Shaved Monkey
1 million = approx 10²⁰ so it only takes 20 foldings over to make a million layers. However, there can't really be a million layers actually present. If a sword is 1cm thick (for ease of calculation), each layer, if coherently identifiable would be 10^-10m thick, or 1 atom. Given that some irregularity and mixing must occur at each stage I wonnder how many real layers can be produced and if only 100 or 1000 layers can really be demonstrated, is any additional folding just for show or does it have other useful physicochemical effects?

Sad that someone who is looking so lovely today could be so sloppy about math. 1 million = approx 10²⁰?

~ 10²⁰=approx 100000000000000000000

1,000,000 <> approx 10²⁰

[Badly Shaved Monkey]

Originally posted by TeaBag420
Sad that someone who is looking so lovely today could be so sloppy about math. 1 million = approx 10²⁰?

~ 10²⁰=approx 100000000000000000000

1,000,000 <> approx 10²⁰

Oops, big monkey fingers, little monkey brain.

That would be 2²⁰

I see now why you hairless maggots rule the planet.

[Matabiri]

Originally posted by Xeriar
No, the folding was done to remove the impurities from the rather poor iron they had to work with. That effect was caused be dual tempering - cooling the edge of the blade at a different rate than the back.

Sword Forum International hammers out the details. Some blades were folded ten or twenty times but, naturally, they fuse together (if they don't they risk splitting - very bad).

They don't -exactly- fuse, otherwise the layers would not be detectable. It's not just removal of impurities, but also grain refinement. The carbon diffusion distance is also less than the thickness of a layer, so the metallurgy will change from layer to layer, giving a laminated effect which will make the sword better mechanically.

These may simply be additional effects, but they do exist.

[kookbreaker]

Originally posted by jzs
Sorry. I never have used my sword on another person, and never plan to. In fact, I will avoid that at all costs.

It has been pointed out that there is a disporportionate number of replica combat fighters in the JREF forum. Not only the SCA stick jocks, but also many SCA fencers, and other period fencing groups as well. Anyone trying to hold their sword experience over others around here is not to be taken very seriously.

All of us have safety standards to prevent facing live steel. I hvae found that those who (claim to have) faced live steel are often not very competent and are overstating their skills. It seems that facing real 'live steel' matches is more of a macho event than a way to determine real period fencing skills.

That said, having my own experience with swordplay and swords, I can say that Katanas "ain't all that" and Kendo is ill-suited to face most western styles. (Katana vs. Armorer Knight = Bad, Katana vs. Rapier= Bad, Katana vs. Gun = Very bad)

[Bikewer]

Kendo is not quite the same as Kenjutsu, the combat technique.

This argument goes on constantly on dedicated forums like Swordforums and Bladeforums.

The Japanese sword technique evolved over centuries (feudal Japanese warred viciously with themselves for over 500 years), and was quite varied. Long weapons meant to be used from horseback were gradually replaced by the standard pair of swords worn by the Samurai classes; one long (generally called the Katana) and one short (wakizashi). That's simplified, there are all sorts of sub-classes of these weapons.

In warfare through the Warring States period, large numbers of heavily armored Samurai would face each other with individual duels taking place for some time, eventually descending into a general melee. Bows, spears, halberds, and other weapons would be employed on the battlefield as well. Huge numbers of casaulties would result. Armor was light, flexible, and efficient, allowing freedom of movement and good protection against both cuts and thrusts.
Later, after the "restoration", the Samurai classes were outlawed, and thousands of Samurai fighters were cast adrift to become Ronin, a period from which we have most of the classic Samurai stories like Musashi, The 47 Ronin, and many others.

Somewhat romanticized, there was nevertheless a "culture" of ex-warriors wandering about and challenging each other to duels.
Musashi evidiently killed about 60 people, finding "enlightenment" in the process!

The sword techniques used by the Japanese during this period were developed for a specific culture and specific opponents, and to wonder "what if" they bumped up against European knights, Spanish rapier artists, or whatever, remains pretty much speculation.

I recall that the Englishman, Silver, had a poor opinion of the "long, skinny" swords used by the Italians and Spanish, and felt that a good stout shortsword was a superior weapon. Whoever did the Liam Neeson version of Rob Roy must have been familiar with these ideas, to judge from the final duel scene.

[Vitnir]

I remember that I have read somewhere that swords in general was a upperclass "show off" weapon and not a very good one on a battlefield against other types of weapons such as spears etc. Anyone know more about this?

[Hellbound]

Originally posted by Vitnir
I remember that I have read somewhere that swords in general was a upperclass "show off" weapon and not a very good one on a battlefield against other types of weapons such as spears etc. Anyone know more about this?

While swords were functional weapons, not just show, a decent spearman or staffman can take out a skilled swordsman. Likewise, a skilled staff or spearman can take out an expert swordsman (geenrally speaking). In combat (not ritualized duels or some other artifical structure that limits action), reach is probably the most important factor. You have to be a much better swordsman to beat a skilled spear weilder than to beat another swordsman.

Reach fueled the process of weapon development, really. From simple tools (axes, swords, etc) developed longer weapons. Spears got longer and became pikes, ransuers, or spetums. Axes grew into halberds. Picks grew into bec-de-corbins. Cleavers grew to glaives. Bows went to longbows, and crossbows got bigger for more power and longer range. The development of firearms was a huge turning point. Even thought the early guns were almost as likely to kill the weilder as the target, they were still a huge advantage in battle, and pretty much ended the battlefield superiority of the armored knight.

Even today, reach and range are important factors in war.

[FreakBoy]

Originally posted by TeaBag420
Anyone in this thread who's ever actually used a sword on someone else using a sword please raise your remaining hand.



Does it count if it was Slow-mo sparring? Even slow-mo.... pretty hairy stuff to do.

[kookbreaker]

Originally posted by Vitnir
I remember that I have read somewhere that swords in general was a upperclass "show off" weapon and not a very good one on a battlefield against other types of weapons such as spears etc. Anyone know more about this?

As to sword vs. spear it mostly matters as to who is weilding what as to which is "better" however, if you take well trained 500 spearsmen and put them up against 500 well trained swordsmens in a pitched battle it should be the spearsmen who win. The spear is in the 'works well with other' category and a nice spear wall makes a tough nut to break if all you have are swords.

On the other hand, there was an incident in Rennaissance warfare where a bunch of short swordsmen with Targ shields ran up to a conventional pike block and worked their way under the pikes. They proceeded to hack away at the helpless pikemen (who carried no other weapons). After that it was generally ensured that all Pikemen carried some sort of sword, rather than depending on specialists (Halberdiers, Dopplesoldners) within the Pike block. Wish I had a link...

[Vitnir]

Thanks Huntsman, I didn't mean swords were useless. The swords has naturally the advantage that you can carry it with you everywhere, so you have a pretty good defensive weapon against e.g. robbers. You could probably also use it in the same way people are using their cell phones or exclusive clothes today, to brag to everyone how sucessful they are, how much money they got and that they have connections to advance on the waiting list for that exclusive swordsmith. On a battlefield they might be easily defeated by a peasant with a sharpened pole?, embarassing.
Presently I have bought two knifes made by blacksmiths, but I forgot to ask them what steel they used, techniques etc. A long sword made by a blacksmith would cost way to much I think, I can imagine they would have to spend like 20h to make one?

[Bikewer]

Even Mushashi, in The Book Of Five Rings, said that the halberd, (Naginata) was the best battlefield weapon, provided there were room to use it!

Interestingly, Silver (above mentioned) said the same thing about the Bill-Hook, another polearm used in similar fashion.

[Xeriar]

Originally posted by Huntsman
While swords were functional weapons, not just show, a decent spearman or staffman can take out a skilled swordsman. Likewise, a skilled staff or spearman can take out an expert swordsman (geenrally speaking). In combat (not ritualized duels or some other artifical structure that limits action), reach is probably the most important factor. You have to be a much better swordsman to beat a skilled spear weilder than to beat another swordsman.

Spears are often underestimated, and as I understand it swordsmen were often the 'elite reserve' - to handle both spear and flail types, but I'm not so certain.

It partially depends on the type of spear and sword, and partially on the terrain - many spears were meant for formation work, while few would be as agile all alone in an open field. All the swordsman has to do is get close (easier said than done at times) - but once it happens - dead spearman.

[Xeriar]

Originally posted by Vitnir
Thanks Huntsman, I didn't mean swords were useless. The swords has naturally the advantage that you can carry it with you everywhere, so you have a pretty good defensive weapon against e.g. robbers. You could probably also use it in the same way people are using their cell phones or exclusive clothes today, to brag to everyone how sucessful they are, how much money they got and that they have connections to advance on the waiting list for that exclusive swordsmith. On a battlefield they might be easily defeated by a peasant with a sharpened pole?, embarassing.
Presently I have bought two knifes made by blacksmiths, but I forgot to ask them what steel they used, techniques etc. A long sword made by a blacksmith would cost way to much I think, I can imagine they would have to spend like 20h to make one?

Depends on what you want. Angus Trim blades are held in high regard and cost a few hundred dollars. There are some specialized workshops that have waiting lists measured in years and you can expect to pay several thousand for them.

[JSFolk]

I'd like to add that there are many differnt types of stainless steel, and to say "avoid stainless swords at all cost!" because of one incident with a cheap replica katana is rather hasty.

I tend to stay out of the sword discussions on Bladeforums for two reasons. A) Swords nowadays are pretty anachronistic and useless and B) If I read too much, I'm sure I'll buy one. :D

[Crossbow]

Originally posted by SkepticJ
Does anyone know where I can read about why some samurai swords were made with over a million layers? What effects did having the blade like that do? How easily did Asian swords snap off latterally? I've heard they were quite bad about doing that compared to European swords. Anyone know? Thanks.

In some ways, Japanese swords were better than European, however Japanese swords did break. There are many accounts of such things happening.

However, most Japanese swords were made with only one striking edge, whereas most European swords were made with two; so the European models permit some moves which are very difficult to do with the Japanese models.

By the way, I have done a good bit of SCA fighting, and I have done some without armour. However, I have never done any fighting with real swords and I sure hope that I never do!

[Hellbound]

Oh, for those with questions about forged blades:

I purchased my longsword from a place called Highland Armoury, out of North Carolina. He uses industrial spring steel for all his blades, has European and Oriental versions on hand, and will special make requests. He also garauntees his blades for as long as he's alive (if it breaks, he'll make you a new one). I paid about $150 for mine, but he gave me a military discount. I believe regular price was about $180.