Why does the KATANA have a curve?

#shorts #sword #katana #swords #samurai

[thecornerkid]

I’m loving these shorts, Shad. Quick bits of trivia about swords.

[tyriquesmith]

I'm glad Shad started doing these shorts. It's gotten me interested in a lot of videos I may have skipped over before.

[DarthBiomech]

I thought it was curved to make it a bit easier to take quickly out of the sheath, curious to see that the bend is actually almost unintentional.

[Han-rwev]

I like the way Shadiversity has 'grown'.

It's fun seeing more people on the team and seeing their different perspectives and how they interact with each other.

I have to admit I was kind of concerned about Shad being less 'involved' at first, but it's turned out better than I expected.

I was a bit dubious about the shorts as well, but they're like little refresher courses at the 'Versity..

Anyway, I'm wondering when there's going to be a Shadow of the Conqueror sequel..

[LordBloodraven]

Knight: "I use a longsword."
Samurai: "I use a katana."
Astartes: "I use a chainsword... FOR THE EMPEROR!!!"

[AhmadSattout]

Katanas be like : "it's not a bug... it's a feature!"
Hundreds of years ago

[JustTooDamnHonest]

Money doesn't buy you happiness, but it buys a lot of swords.

[Sophia-vkbq]

I hear those warriors from Hammerfell have curved swords. Curved. Swords.

[rvcloud]

Excellent work Shad, definitely appreciating this series on debunking katana myths, but to add to your list of things to test with the katana, I've been taught that curved blades in general perform better on the draw cut specifically. (Other examples are the saber, talwar, etc, etc.) Matt Easton might have some more info on that, but from my martial experience, with a katana we were taught to cut a specific way that includes the drawing motion (regardless of the actual cut) to make the most effective use of the blade geometry. You might find biomechanically you naturally do this to a small degree in the cut, which any curved would theoretically take advantage of. Good luck debunking more myths!

[KingNovea]

The curve helps many different aspects of katana, it's more on purpose than something that happens

[stuborn-complaining-german]

The explanation was good, but the curving during quenching is actually not because there is more metal on the back. It's because, while the edge basically "freezes" in its high temperature crystal structure, the backside has enough time to change back into a crystal structure that is a little bit more compact. That's why the backside shortens a little bit during quenching pulling the whole blade into that curve.

[ryuuronin]

I feel like a broken record, but: the slight curve is also incredibly helpful for the quick draw. Being able to quickly get the sword out of its sheathe, and even attack in the same drawing motion, is integral to it's use as a backup wespon and a self defense tool. So much so there is an entire school of combat baswd around it.

[tenclosed]

the unkown curve affect was kept over the years cus it was easier to draw out of the sheath. a slight curve sword cuts better than straight sword. if you dont like that fact its your problem

[tiber_drake]

If that were the case, the katana's curvature would be inward rather than outward (because differential hardening cools the blade faster than the butt, and the metal shrinks as it cools). In fact, the bend of the katana, like on many other swords with a single-edged blade, is caused by the fact that when the edge is forged, the metal under the hammer blows moves apart in all directions, thus increasing the width of the blade and bending the spine. This is very easy to check if you take a strip of metal of the same thickness, mark it along approximately in the middle, and start hitting one half with a hammer, thinning it. After a while, the other half will begin to bend. I'm surprised Tyrant hasn't mentioned this yet)

[lihisluikku]

Yeah I think when people say cheaper vs expensive katana, they don't mean 300$ vs 1000$+.

Instead I believe most people when they say this, mean that a properly made sword (which usually costs around the 300$ mark), is a huge leap from what is usually called a "mall katana". But this obviously applies to all swords.

But for the typical mall katana, there are usually fitting issues. Usually the steel is of poor quality not fit for tools or blades. Sharpening is done poorly. And most critically, these swords often have small and narrow tangs, prone to snapping when you cut.

This makes such swords dangerous.

[adamblakeslee]

It's also a holdover from the earlier Tatchi and Odatchi swords which had a more pronounced curve.

[timothygooding]

how did I not realize until now that the curve forms because the entire sword is shaped as a single wedge - that way it quenches slower near the rear and thus has a better ability to absorb impact energy with the rear while the cutting edge hardens fastest and thus is the hardest (and most brittle) part

No weird precise quenching technique needed (at least on the broad end) to get just the right characteristics

[UncleMikeDrop]

You are the first creator I have seen explain the incidental and marginal curvature of the katana. THX

[uexkeru]

A certain Japanese history youtuber researched this and found that early differentially hardened blades were reverse-curved before quenching to get a straight blade in the finished product. So the most likely reason for the curve is actually that they started wanting a curve to make the sword cut better in combat. Uchigatana evolved from "tachi" that were longer, more curved and more distally tapered. A sword or polearm would be used from horseback to slice through the skull at a point anywhere from the neck to just below the helmet - where an average soldier is least protected (look up Kamakura battle wounds for papers discussing this).


Many koryu guys will also tell you that the curve affects the dynamics of blade contact between two swords and gives them a slightly different way of doing it than the German styles

Edit: Also, "warebetito" short swords in the Heian era existed with both straight and curved blades, and they were certainly cutting weapons for foot soldiers. The smiths seemed to be curving or straightening them according to preference.

[mriddley]

I love this channel it really teaches me a lot about swords and it doesnt really insult anyone for their own preferences it just gives the facts and leaves it at that