A really good sword

[Jinumon]

Originally Posted by DanHoward

We've already shown that this is a load of bollocks. They had single-edged straight swords before the 9th century that were differentially hardened and there are plenty of curved Japanese swords that were not differentially hardened.

You would almost certainly know better than I. But weren't the Chinese influencing Japanese military technology as early as the 7th century? The Chinese fought against the combined forces of Korea and Japan in the Battle of Baekgang in 663. And I myself own a historical reproduction of a Tang dao based on a 7th century archeological find.

Originally Posted by DanHoward

Only against a flat surface. Humans are not flat.

I'm not a physicist or an engineer so, again, you almost know certainly better than me. That said, I was under the impression that even against targets through which an edge passes completely, the surface area is increased somewhat by the addition of a curve. This video (timestamp 22:35 - 28:51) does a decent job of illustrating the point, I think, though the gentleman in the video is not himself an expert to my knowledge.

Originally Posted by DanHoward

Only some Japanese swords were made like this and probably not the majority of them.

I'm referring specifically to the typical "traditional" katana/tachi constructions, though I realize that the word "katana" simply translates as "sword" in Japanese and is of limited use. As with any historical weapon, I can imagine that there were an infinite number of variations in construction, materials used, and overall quality of the product. With that in mind, were most katana/tachi not constructed with soft spines, the inclusion of habaki, high-carbon steel edges, and quenched in water? Honestly I'm just curious.

Jinumon

[DanHoward]

Originally Posted by Jinumon

I'm referring specifically to the typical "traditional" katana/tachi constructions

So am I. Only a minority were made in the manner you describe. Others had a steel edge forge-welded onto a soft core but not heat treated - just work-hardened. Some were made from a single piece and not heat treated - just work-hardened. Some were made using a hard and soft piece that were folded and forged-welded together to create medium carbon steel that could be differentially-hardened, or not. Some were made from soft iron with no hardenable steel at all. Japanese swords were made using the same variety of techniques that were used all over the world. Some were good quality, many were not. A tiny percentage were excellent quality. Just like everywhere else in the world.

[Jinumon]

Originally Posted by DanHoward

So am I. Only a minority were made in the manner you describe. Others had a steel edge forge-welded onto a soft core but not heat treated - just work-hardened. Some were made from a single piece and differentially hardened. Some were made from a single piece and not heat treated - just work-hardened. Some were made using a hard and soft piece that were folded and forged-welded together to create medium carbon steel that could be differentially-hardened or not. Their swords were made using the same variety of techniques that were used all over the world.

I realize it isn't your job to personally educate every historical weapon enthusiast who's come across some bad sources. Do you have any links to or suggestions of sources of actual historical information Japanese weaponry that I might peruse? Anything relating to the Samurai or historical Japan frequently has so much mystique wrapped around it that I can't tell the difference between actually sourced historical information or self-perpetuating myth.

Jinumon

[DanHoward]

A good book to start with is Bottomley and Hopson's Arms & Armour of the Samurai.

If you want to see how bad swords are at cutting armour then look at this:
http://www.shinkendo.com/kabuto.html

Here we have a 500 year old helmet (so not in the best condition) placed at optimal height on a rigid, non-moving surface and was cut by a master swordsman wielding a blade that was specifically made for the task. The edge was sharpened by a master polisher and the sword was swung using a technique that would never have been employed in battle (i.e. it was heavily biased to favour the swordsman). The best he could manage was a "world record" 13cm (5.1") cut that was so shallow that it wouldn't have scratched the scalp of someone who was wearing it.

[Jinumon]

Originally Posted by DanHoward

Here we have a 500 year old helmet placed at optimal height on a rigid, non-moving surface and was cut by a master swordsman wielding a blade that was specifically made for the task using a technique that would never have been employed in battle (i.e. it was heavily biased to favour the swordsman) and the best he could manage was a "world record" 13cm (5.1") cut that was so shallow that it wouldn't have scratched the scalp of someone who was wearing it.

I knew these guys were wearing helmets for some reason XD

Jinumon

[Tomsdad]

I was also a long time believer is the "differential hardening caused curved katana blades" theory but it was then pointed out that earlier Japanese straight single edged blades were also differentially hardened. So the smiths obviously knew how to produce other blade shapes with differential hardening, suggesting it was a choice. Certainly they could have compensated for the effect if they had wanted to. EDIT: On top of this as DanHoward points out not every Katana with the stereotypical curve were differentially hardened


The argument for benefits of a curved blade that I tend to agree with are:

1). Certain cutting actions against bare flesh (not every target was armoured and not every blow in combat had to get around armour).

2), Being on a horse and staying mobile favours certain attacks where having a curve helps*

2). Edge alignment when hitting being helped by a curve


These three kind of combine. i.e. if you are on a horse and riding through fleeing poorly equipped foot troops and have very short windows of opportunity and having to worry about staying in your saddle.



But two big points when it comes to samurai & katana's etc

1). it was never the samurai's primary weapon either when on foot or horse back. Although yes you still want your back up weapon to be as effective as it can be in the most likely situations you fight in case you do need it. But non combat factors can become more relevent than they'd otherwise be.

2). Generally** it wasn't that curved when compered to other curved blades (and curved blades used from horse back)

Originally Posted by Jinumon

I knew these guys were wearing helmets for some reason XD

Jinumon

Heh quite, armour was generally some combination of expensive, difficult and time consuming to make. Even more so when you put it in the context of equipping troops that you want to deploy. And yet despite that and it coexisting with weapons for thousands of years it never went out of style so I think it is safe to assume it did it's job against weapons enough to keep around.

Even when guns improved past the ability of armour to be effective against them in terms of efficiently deploying troops with it, it didn't actually take that long*** for advances in armour to make it competitive again.





*Although it's not 100% one way, there was big debate in the C19th regarding straight'n'stabby or curved'n'slicey for horseback (albeit it was being discussed in the C19th context). Debate finishing just in time for WW1!


**there's a range in the historical record because "katana" is actually a pretty general term, and it has covered lots swords for a long time


***in terms of the history of armour wearing anyway!