How Japanese Masters Turn Sand Into Swords

This is a video about how Japanese samurai swords, aka katanas, are made - from the gathering of the iron sand, to the smelting of the steel, to the forging of the blade. Head over to hensonshaving.com/veritasium and enter code 'Veritasium' for 100 free blades with the purchase of a razor. Make sure to add both the razor and the blades to your cart for the code to take effect.
Special thanks to our Patreon supporters! Join this list to help us keep our videos free, forever:
ve42.co/PatreonDEB
If you’re looking for a molecular modeling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - ve42.co/SnatomsV
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A massive thank you to John McBride for making this entire project happen. This would not have been possible without John. Please check out his japan walking tours walkjapan.com/
Massive thanks to Craig Mod, Inoue-san, everyone in the Tanabe family, and Takanashi-san. Also a massive thank you to Kevin Cashen - cashenblades.com/
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References:
Tanii, H., Inazumi, T., & Terashima, K. (2014). Mineralogical study of iron sand with different metallurgical characteristic to smelting with use of Japanese classic iron-making furnace “Tatara”. ISIJ international, 54(5), 1044-1050.
Tate, M. (2005). History of Iron and Steel Making Technology in Japan Mainly on the smelting of iron sand by Tatara. Tetsu-to-Hagane, 91(1), 2-10.
Krauss, G. (1999). Martensite in steel: strength and structure. Materials science and engineering: A, 273, 40-57.
Krauss, G., & Marder, A. R. (1971). The morphology of martensite in iron alloys. Metallurgical Transactions, 2, 2343-2357.
Yalçın, Ü. (1999). Early iron metallurgy in Anatolia. Anatolian Studies, 49, 177-187.
Kapp, L., Kapp, H., & Yoshihara, Y. (1987). The craft of the Japanese sword. Kodansha International.
Matsumoto, C., Das, A. K., Ohba, T., Morito, S., Hayashi, T., & Takami, G. (2013). Characteristics of Japanese sword produced from tatara steel. Journal of Alloys and Compounds, 577, S673-S677.
Inoue, T. (2010). Tatara and the Japanese sword: the science and technology. Acta Mechanica, 214(1), 17-30.
Images & Video:
Great video from NHK - ve42.co/NHK
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Special thanks to our Patreon supporters:
Adam Foreman, Anton Ragin, Balkrishna Heroor, Bill Linder, Blake Byers, Burt Humburg, Chris Harper, Dave Kircher, David Johnston, Diffbot, Evgeny Skvortsov, Garrett Mueller, Gnare, I.H., John H. Austin, Jr. ,john kiehl, Josh Hibschman, Juan Benet, KeyWestr, Lee Redden, Marinus Kuivenhoven, Max Paladino, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, Richard Sundvall, Sam Lutfi, Stephen Wilcox, Tj Steyn, TTST, Ubiquity Ventures
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Directed by Petr Lebedev
Written by Petr Lebedev and Derek Muller
Edited by Trenton Oliver, Jack Saxon, Peter Nelson
Animated by Fabio Albertelli, Jakub Misiek, David Szakaly
Filmed by Petr Lebedev and Lui Kimishima
Produced by Petr Lebedev, Derek Muller, Han Evans, Giovanna Utichi, Emily Taylor
Additional research by Gregor Čavlović
Thumbnail by Peter Sheppard
Additional video/photos supplied by Getty Images
Music from Epidemic Sound

[@mackerel9026]

man open youtube, man see sword, man happy

[@dragonofmight3971]

real

[@Kavaitsu]

Nice pfp btw

[@gustavl3107]

Man read comment, man upvote

[@Lunk42]

Literally me

[@konradk1066]

Man watch Shōgun, see Katana video, man click

[@shangerdanger]

finally a video that's just about material science so a dumbass mechanical engineer like me can understand it lmao

[@joecordero1699]

Bsme gang let’s goooo

[@lpc9929]

Hey Google

[@gaveintothedarkness]

Same here, the math stuff just goes over my head.

[@calholli]

This stuff is undoubtably cool... But modern day CPM super steels are far superior than this old classic style of making swords.. (CPM is crucible particle metallurgy)

[@hoochill]

you like phase diagrams?

[@christophermolitor4554]

Props to Peter, this must've been intimidating at times and he did a great job being respectful and appreciative of the opportunity.

[@konstantinospalapanidis6414]

"Whatever you do you should do it with deep care, attention to detail, and love for the craft" So true.

[@AAbattery444]

Do you guys remember when shows like planet earth and the discovery channel pumped out interesting documentaries with this level of production quality? I miss those times. Shows just don't feel like this anymore. Thank you for bringing back that feeling veritasium. You guys can't get enough credit.

[@theastuteangler9642]

man, when discovery channel dropped in the mid 90s, it was insane the level of production, the knowledge, the narration.

[@dimitar4y]

(((they))) want you to be stupid. Stupid pays 90% of their work as tax that .. Honestly I got no idea where it all goes. But this ain't no 'spiracy.

[@nes999]

Imagine if they had TV channel level budgets and power

[@michaelmoorrees3585]

Because they went for low hanging fruit, resulting in the likes of Ancient Aliens.

[@dimitar4y]

because corporate hires morons who do nothing but excuses, accountants that reduce costs until there's nothing left, lawyers so they can cheat people and get away with it. All in the name of "Profit".

[@neophoys]

<a href="#" class="seekto" data-time="1100">18:20</a> slight error here: The combination of Ferrite and Cementite is Pearlite, not Perlite. Perlite is a volcanic glass, mostly made of silicates and used in gardening for its high porosity that helps to aerate the soil and provide microrefugia for microbes.

[@helloidharbl6753]

** deep inhale** NNEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEERRRRDDD Just messing with ya. Knowledge of such things is cool.

[@thorwaldjohanson2526]

The spines usually also don't have enough carbon to form a pure pearlite structure, rather a ferrite-pearlite structure.

[@jakeleclaire7786]

It’s “Leviohsa” not “leviosa”

[@gingeral253]

Wowzers

[@fubbernuckin]

thank you for this. I knew about perlite from gardening and furnace concrete, and I was very confused when they said that some white volcanic gravel was the same thing these swords were made of.

[@andrewmyers2920]

such a beautiful combination of geology, chemistry, physics, history, and craftsmanship

[@dazingamaine4318]

truly awesome. nice to see an alien presenter. they truly look almost human.

[@roostewrum]

Sooo.... "metallurgy".

[@pamtnman1515]

Agree. Wish they had included the handle and scabbard parts too

[@jooei2810]

Don’t forget mysticism.

[@user-tp5tf5gs3l]

As a Japanese native, I can’t thank you enough for making a video on this subject. The metallurgy associated is just so fascinating and getting the neat graphics and explanations was awesome. Thanks for spreading the Japanese culture!

[@FenrirRobu]

This video is made with care and a lot of effort. However, are you aware of the inaccuracies presented here?

[@toshiyukisaito8757]

Hi Veritasium and Derek. I'm a descendant of a Katana blacksmith in Japan. The craft in my family has been continued up to the end of Edo era and no one is a blacksmith anymore, but my family had swords inherited from our ancestors. Thank you very much for your appreciation for the art of sword making in Japan. I enjoyed this video more than any other videos of yours since I found you 9-10 years ago. I've watched every single one of them since then.

[@GluStiKk]

Can I have one and can you teach me how to make a sword!!!

[@annoswet1576]

@@GluStiKkhe literally just said they are not blacksmiths but their ancestors were :p

[@GluStiKk]

@@annoswet1576 i want a new sword bro wtf😡😡😡😡

[@ink9812]

Tell me you're rich without telling me you're rich. "Oh, we have a few swords from the Edo period". You're so lucky

[@annoswet1576]

@@GluStiKk just make your own sword from a cardboard box. We call that the poor mans katana.

[@Darockam]

What amazes me is that we're now perfectly able to explain in details all of the mechanisms involved along a process that emerged solely from trial and error. Science is amazing.

[@pablo.pereyra]

And we can produce better quality steel in less time and more quantity.

[@traplover6357]

This ^^^ Love that science explains the why part

[@Rom2Serge]

Now we have thousands types of various steels , supper alloys , the modern drill bit made out if tungsten alloy may easily drill trough the best of Japanese swords. Agree science went a long way .

[@lbaxel9122]

Insane people were able to figure everything out like that before science

[@ViktorRzh]

@@pablo.pereyraYep. And lets say, if you dig throu how this industrial processes were discovered. It was literally like - old dude with a dozen generations of experience and a few kids with mechanical engenering knowlage. And they actually figured this out even before science catched up. Early books on subject may casually reference alchemical works because it was a base understanding.

[@spidernevi]

This must be a very epic journey for him. The forging process itself is an epic ritualized group efforts

[@kajeralocse]

I love how they preserved the rituals involved such as praying. This takes the hardwork and output beyond physical realm, to a spiritual realm. It gives meaning to what they're doing. The level of faith and respect to the elements is astounding. Thank you for showing this to me Veritasium!

[@lucdercourt9791]

For that price it better be brimming with haki.

[@smallpatatu]

For that price Ryuma should come to my house and give it to me 😂

[@kryeohs]

and a full training course with mihawk

[@Diamondthetimewaster]

Bruh

[@Canetoady]

F

[@Richard_Nixon-mr6rq]

???

[@nadabutsi7537]

Small correction. By folding the steel you will actually lose a lot of steel due to slag and pieces flying off, the more layers the more material loss will happen. Alec Steele on youtube who specialises in modern damascus talked about this in one of his videos

[@xakstyles]

Which is probably why it's only folded 8 to 13 times. 35 years ago, I watched something that talked about them being folded 1,000 times +, they must have not understood how the layers form

[@spcraftsman2656]

@@xakstyles"if it's good, let's do it a thousand times. that'll make it better, right?"

[@FenrirRobu]

​@@xakstyles it's another marketing trick, saying folded to mean the number of layers formed rather than the number of actions performed.

[@vishnusankar5364]

Hi Peter, it's a great video. I liked the way you explained each process even though I knew few processes i didn't know why they are for. Thanks for the clarification. I appreciate that you are grateful and you had a huge respect for the opportunity you got. All the best. Looking forward for the next video.

[@shangerdanger]

meanwhile i can craft a steel dagger in skyrim in 4 seconds. we've come so far

[@falxonPSN]

Indeed. And if the old commercials are true, when the PlayStation 9 lands, you'll be able to do it by thought alone!

[@MrSerCeMan]

Considering the direction in which modern gaming is going, you'll be able to do it in just 1 second soon... because that's how long it takes to do a microtransaction.

[@onlyonecannoli7537]

Ah yes 14 damage don't think you'll cut through the carpet tho with that 😂

[@ThePWNDR]

it’s the guy who thirst traps with fish omg!! hi can i have one of ur gfs

[@wl5420]

Yo so true!

[@Flames-dp6hw]

I absolutely enjoyed this one. I knew a little bit of the sword making but I learned so much about the steel smelting that I had never heard of before. Absolutely amazing!! Thank you for creating this!;

[@pjaywils6073]

Have watched several videos showing the making of Japanese swords. Always interesting to watch. This video is no exception and I'd like to say many thanks for clearly explaining the science behind how the various steels are combined to produce the swords. Very informative 👏 👌

[@anandakrishnan45]

"whatever you do, you should do it with deep care, attention to detail and love for the craft. Do that enough times, and you might just make something wonderful" - Veritasium

[@stevdor6146]

whatsoever ye do, work heartily, as unto the Lord, and not unto men; knowing that from the Lord ye shall receive the recompense of the inheritance: ye serve the Lord Christ. -Col 3:23-24

[@emailformosa]

_… __-wonderful-__ beautiful”_

[@digl_live]

Probably one of his writers tbh. I'm not sure he writes any of his videos anymore.

[@The_Random_Bastard]

WTF??? did you even see the previous video with rods of god ?:D:D:D if they would follow what in your comment they would not take such huge L

[@sportyeight7769]

We often forget the most important part. You will suck hard at it at first, then you'll become average, then maybe you'll become great.

[@Exilum]

<a href="#" class="seekto" data-time="1418">23:38</a> I love that because he bowed much lower than him, he felt compelled to bow a second time. You bow at different levels depending on how respectful you're being and the context, so him doing a 90° bow was probably very unexpected. You can''t not feel bad if someone bows 90° while you didn't 😭

[@ahobimo732]

I guess you can't tell how low the other person has bowed until you coming back up! 🤭

[@NihongoWakannai]

​@@ahobimo732 you don't need to look, you should generally know how low to bow based on the social situation you are in

[@dolgolae]

I noticed this too, I was really shocked at how low he went it almost felt like he was apologizing 😂

[@Interspirituality]

@@ahobimo732thats deep

[@robictibay5747]

How about a 180 degree bow huh?

[@EnzoDraws]

This is one of my favorite Veritasium videos of all time and I did not think I would say that in 2024. I love all your videos, but this? This is an all-time great. This was truly incredible and fascinating.

[@Znatnhos]

One of my father's favorite pieces of advice is "anything worth doing is worth doing right" and these Japanese artisans take that philosophy to the extreme.

[@alexv3357]

"Never half-ass two things. Whole-ass one thing." - Ron Swanson

[@segueoyuri]

I've also heard people say "the way you do something is the way you do everything". This Japanese meticulousness and perfectionism pervades their culture everywhere you look. Veritasium posted a video about the blue led just the other day, it's a very good example of that. Once they put their mind to something, doesn't matter how hard it is or how many hours of work it takes... It'll be done

[@thecookiemaker]

reminds me of Amish furniture. My friend bought an entertainment center to put his tv and stereo system in. The back side of the piece that is never seen since it is up against a wall is just as detailed and well built as the front that gets all the eyes.

[@n0m4nic]

Now if only they knew what they were doing. Spring steel is far superior.

[@jdapaul1351]

Explains Toyota's jidoka and kaizen principles.

[@SnootchieBootchies27]

What I find amazing is that they figured this out through experimentation and intuition, without actually needing to understand the chemistry involved.

[@SariahPendragon]

These swords are literally the physical embodiment of trial and error in a form that cannot be perfected further, and as you said, without understanding the molecular science. Japanese swordsmiths are geniuses.

[@bass-dc9175]

@@SariahPendragonUhm ... I mean they did the best they could but traditional japanese katana were vastly inferior in terms of the steel it used, over European swords. Let alone modern ones. Saying the smiths of that time were highly skilled and did the best they could is valid. Saying they reached a "form that cannot be perfected further" is assinine. Modern mass-produced steel katanas will beat any traditionally crafted one in terms of performance. (And the "Traditional" needs to be put in quotations too, since the sand used as ore is sifted with electromagnets. Older Katanas have far more impurities than modern "Traditionally" crafted ones)

[@ingerasulffs]

@@bass-dc9175 Could you share a source or two for the statement "traditional Japanese katana were vastly inferior in terms of the steel it used, over European swords"? Thank you. I did my 20 minute research and in the 3 places I had time too look it turns out the Japanese traditional steel was not at all inferior to European traditional steel.

[@iotaje1]

@@ingerasulffs People did a number of tests, for instance striking the swords with one another. The japanese sword breaks in half, not the European one. Japanese swords are also much thicker and heavier, this is evident when you see that a Katana is used two handed despite having a very short range. It is also sharpened on one side only and not very good at stabbing, which is how you best use a sword in war. The reason for this is that the Japanese smelting process produces lots of low carbon iron and a small amount of high carbon steel. In order to make a useful weapon the smith must forge weld many different pieces together and they are very good at it. Europeans use a single piece of high carbon but springy steel, which makes the blade very tough, and the outer layer is hardened by cementing aka case hardening. The japanese barely used their swords in combat, it was a status symbol so it's battlefield performance didn't really matter.

[@markn6941]

@@iotaje1BS...google is free bro.

[@tommcclelland119]

Truly amazing. Thank you for sharing this experience.

[@TAPOUT5282]

Thank you for all the time and work that went into this video. Thank you very much for sharing this amazing video with us

[@Suicidekings_]

When I was a Blacksmith's apprentice many years ago, I was told by my Master that slag came from Dragons. The dragon would sneeze into your forge if you looked away, and leave behind the giant dragon's booger. Everyone, even the most experienced smith, will look away from there forge. The story is told to enforce the idea that it is important to always keep an eye on your forge. The reason it's important to remove the slag is because it draws heat away from your forge, and subsequently your material.

[@jackbrax7808]

Slag is also impurity that will weaken your steel.

[@hugedickerinokripperino5299]

Their*

[@faramund9865]

Where is your master from?

[@Teraplexor]

Earth​@@faramund9865

[@yourhandlehere1]

Hahhaa! He's just messing with you man. It doesn't matter if glance away or not. They will sneeze in there while you blink.

[@JoeSmith-bs1kt]

Peter is such a good producer. Like he keeps getting crazy access to crazy places and then when he's on camera he's just like "it's gonna be great". So humble, but if you know how much work he's doing it's absolutely insane humility.

[@JoeSmith-bs1kt]

Bro he learned basic Japanese for this that's insane.

[@BishopStars]

Katana means Japanese sword

[@veritasium]

You know I'm screenshotting this comment to send to Derek right? -- Petr

[@illeshurkecz5204]

​@@veritasiumToo late, I already did. - me

[@theyruinedyoutubeagain]

Get that raise boy @@veritasium

[@JohnCNewJr]

I admire the respect your producer showed to this art form. Well done.

Imagine spending all that time on a sword just for it to shatter apart in water. I’d be heartbroken.

[@Proferk]

cry in your six likes, sold account

[@harimonting01]

He looked so genuinely happy when he used the sword for the first time. I myself can feel the excitement just by watching.

[@Wordavee1]

And what did he use it for, chopping a bit of bamboo!! Now what will he do with it? Spend years training to use it like the Japanese warriors did? Or put it on a stand on his mantlepiece and tell visitors how craftsmen spent days making finely tempered steel sword, with a razor edge ......for them to look at!!! 🙄

[@harimonting01]

@@Wordavee1Yes, it's an art. They don't use it to kill people anymore. What do you expect?

[@4RILDIGITAL]

The attention to detail in every step of making these swords is beyond words. Not only are they a thing of beauty, but the skill behind them makes them even more impressive.

[@aidrianpatullo598]

i need a 3 hour long version of this, going in much more depth about literally everything

[@Holly_Mike]

Look up the NHK documentary Tamahagane: Miracle Steel of Japan… it’s only about an hour, but it’s more in-depth on the older ways of the tatara steel production process (and where I think Veritasium got the idea for this video.)

[@FatherTedCrilly]

​That was a good doc.​@@Holly_Mike

[@carukkurac]

​@@Holly_MikeI was going to suggest the same documentary, it is really best documentary about katanas I ever saw. Much more in depth about traditional katana making. I am glad I am not only one who saw it

[@tomconner5067]

The curve in the double edged blade increases the rigidity of the edge and prevents excess flexing, keeping the edge at the correct shaving angle and a close shave with minimal skin contact feels comfortable and cool

[@OlexTheGreat]

As an aspiring blacksmith, my favorite science KZbinr posting a video about blacksmithing is like Christmas all over again

[@rangleski3695]

How do you feel about them using modern techniques like the electric hammer? as a lay person, im a little disappointed they werent still using originals methods.

[@dolgolae]

@@rangleski3695not the original commenter but I think as how blacksmiths are more rarer than what is used to be in Japan, I imagined getting apprentices to help hammering would be also a rare occurrence. That’s my theory anyways but I feel the same way with you that I wish it was kept as the traditional ways but I understand to a certain point.

[@PrograError]

@@rangleski3695 IHMO the eHammer is basically like Ai tools (sans GenAi) or even modern farm tools. It's only a tool so much it reduces the effort needed to get to the final product...

[@uGotGot1618]

These swords are incredibly cool and worth every dollar, but just so you know, a cutting device doesn’t have to be all that exceptional to split a bullet without itself being destroyed. You can do it pretty consistently with a run of the mill axe from the hardware store.

[@MiguelAbd]

Man, you're on point. It is such a bad argument to show something so cool as swordsmithing.

[@AlexBesogonov]

You can do it with a butter knife.

[@jmcu17]

I've seen someone do it with a butter knife. Not impressive at all.

[@hanjarake_taro]

謎理論

[@Tearakan]

Yeah bullets aren't the hardest materials

[@complexity5545]

Great vid. My inner warrior man was glued to this. Making the steel (stock) was the best part.

[@drunkenghoul]

I love the quality of the video and easy way to present information.

[@ProAlchemist]

As a metallurgist, I'm still amazed people figured this out over time and laid the groundwork for where we are today.

[@traplover6357]

Wondered how many generations it took to form this whole process from raw materials to perfection.

[@redrob6331]

Were tataras used for all iron and steel production in pre-modern Japan?

[@solandri69]

When you consider the state of modern metallurgy, it's mind-boggling thinking of how we got here. You think of all the different elements, different combination of elements, and different concentrations of each element which can be added to make a steel alloy. The different heat treating processes which can be applied to it. And you come up with a staggeringly ginormous number of possible different combinations, each with its own slightly different properties. Countless smiths over millennia tried out different combinations, noted its strengths and weaknesses, and passed that knowledge down to their apprentices, which was eventually collated into textbooks and catalogs of common knowledge. What we know about alloying today is the cumulative total of countless lifetimes of experience spanning thousands of years.

[@calholli]

This stuff is undoubtably cool... But modern day CPM super steels are far superior than this old classic style of making swords.. (CPM is crucible particle metallurgy)

[@eli3998]

​@@traplover6357hell even getting the raw materials is impressive, I'd've never thought of that sand trick, props to whoever figured that out

[@_Mukuchi]

those slices were unbelievably clean, people don't know how difficult it actually is to slice a mat so cleanly

[@cesarkopp2]

I recently discover a well-done sharp machete can do better than most swords, in circumstances where do you need to cut things.

[@_Mukuchi]

@@cesarkopp2 I bet a machete would definitely make the job easier. I was just referring to in battōdo and iaidō, it takes a lot of training and practice before you actually get to cut a real mat, and most beginners either are unable to completely cut through the mat or even if they cut through, the sliced edge is curved and there are split ends of the tatami everywhere. It is hard to slice a tatami mat with a katana in such a way that it results with the sliced pieces to look like it was digitally sliced in a 3d modeling software. (I assume professionals can do even more impressive cuts at a much more slanted angle, his cuts were mostly perpendicular to the mat's side by an angle nearing 90 degrees which in theory is easier but still is impressive nonetheless)

[@jonathanodude6660]

@@_Mukuchi why is that? what is the technique and why is it difficult without it?

[@offeibekoe452]

​@@cesarkopp2qqQ

[@jamievarni1530]

Oh, yes I do! Experience is a bitter teacher.

[@Jayesci]

It is humbling to see the process treated with reverence and honor. No wonder the results are so incredible.

[@DeweyBlanton-ku7db]

You are one of very few outsiders to get first hand experience of this traditional way and thanks for sharing.

[@AntonioFreyre]

whoever did your color grading this time deserves a raise - beautiful looking video

[@animenation7171]

Nah that's just japan

[@RafidW9]

​@@animenation7171moronic comment from someone who knows nothing about editing

[@jg4780]

Mexico and China crying in gray shades

[@averagejoe2307]

@@RafidW9 moronic comment from someone who knows nothing about comedy and sarcasm

[@chiShija]

@@jg4780nah mexico bein graded in near monotone orange

[@user-tr8ze7hs5t]

I never tire of watching swords being made by masters. Especially Japanese masters, because of the great care and ceremony involved. Thank you for another viewing.

[@x0j]

omg heckin japan

[@stirlingnguyen9284]

Simply second to none beautiful work of art! Thank you so much for your videos! 👏🏻

[@briand8090]

What an amazing experience. Thank you to all for sharing this.

[@patrickkirsch1239]

I'm a PhD student in Materials Science and Engineering and I wanted to say thank you for this video. A lot of your work goes into the materials science behind things (the semiconductor/ blue LED video was a great materials science video too) but this went into depth on something similar to the project I work on. It's difficult to describe what I do in grad school to people, so this video is perfect.

[@rodidoesburg4061]

What do you think about material science in building engineering? Is that somewhat the same

[@patrickkirsch1239]

@@rodidoesburg4061 If by building engineering you are asking about more structural engineering/ architectural engineering this is a little different. Materials science and engineering is more of an atomistic approach for how a material behaves. So when a material scientist talks about structure, they are usually referring to the crystal structure (how the atoms arrange next to one another, to build a larger crystal) This is different from building engineering, or at least what I believe you are referring to, where structure means bulk properties like strength, ductility, etc. materials science figures out why a material has a certain strength or ductility based on how it was produced, where building engineering just applies the bulk properties to engineering problems like what steel to use to reinforce a building. Long winded but let me know if that answered your question!

[@cayman7806]

What do you do for grad school? I finished grad school recently and was everything metals (casting, mainly).

[@patrickkirsch1239]

@@cayman7806 I’m looking at how a new additively manufactured steel that the navy uses to weld their submarines and ship hulls together compares to the actual material they use for the ship hulls when it comes to environmental assisted cracking (seawater+ stress+ not a stainless steel = cracking which leads to failure). The navy wants to try and expedite their submarine production and if they can limit the amount of time needed in heat treatment facilities by printing the parts rather than traditional wrought production, they can make more subs. What did you do for grad school?

[@cayman7806]

@@patrickkirsch1239that’s neat. I worked with the Air Force to develop a benchmark casting process that could be used to develop property process structure maps for novel aerospace alloys. Lots of simulation modeling and lots of melting/pouring metal.

[@tigeruppercut2000]

Wow this is actually one of the best explanation videos on anything ever, especially on making katanas. For example, I've always wondered how the curve was made. One day I hope to make my own katana too.

[@naygoats955]

<a href="#" class="seekto" data-time="167">2:47</a> Ah yes the bronze katana technique I haven’t had to use this since the heian era

[@Leoliat]

I was gonna say this dawgg

[@catsmeow3656]

Lmaoo I was trying to find a comment like this

[@ZydenHi]

God dammit

[@RedIsntHome]

I came here to say this

[@0accuracy427]

scrolled for this one

[@jonessmith2068]

Wonderful video done with knowledge respect and the yearning to learn! Well Done!

[@mahdiebrahimzadeh6581]

deep into a cultures, feeling every concept behind ceremony and having sense of being part of that glorious human history. thanks your channel, perfect job

[@Kelnx]

These methods make them more expensive due to the labor involved, but far better steel is made everyday industrially. If there were a reason to do so, a modern sword could be devised using cutting edge technology that could outperform and outlast any sword ever made in the past. So what you are seeing here is not the making of "ultimate swords", but really amazing pieces of art that carry history in them.

[@Bruno-cb5gk]

Yeah, this video is pretty misleading. It's also omitting a lot of information about other swords, making the katana seem a lot more unique and advanced than it actually is.

[@ALittleMessi]

I mean that's the story with almost all specialty made Japanese goods. Could you get something produce in a lab/factory that's technically better? Sure. People pay for the history and culture of it. The same can be said for organic food. Even the debate about AI art will literally come down to "did a human put blood sweat and tears into this?".

[@nateh2652]

Any through tempered spring steel is going to make a superior sword. Shadiversity just did a breakdown on this video, and while painfully long, its really good. It seems veritasium fell victim to a lot of the mysticism surrounding the katana and tamahagane steel.

[@cccccccocckkadoodadloo]

@@ALittleMessiyah you not wrong that logically makes sense however- being a fine furniture trainee (if we talking about straight functionality of swords ignore me but u mentioned art) there is a certain feel that human crafted objects art- furniture posses that machine made processes really really struggle to replicate if at all.

[@cccccccocckkadoodadloo]

My point is- is not always bout the history and culture and yes human craftsmanship can and does produce ‘better’ things even if technically they are not perfect.

[@bass-dc9175]

There are a few things here that require correction or additional information. 1) "They are strong and sharp enough to slice a bullet in half." You can do the same with a $0.5 mass produced, cold stamped butterknife. As Penn and Teller demonstrated. 2) "The method for making these swords has remained virtually unchanged for hundreds of years" Both the gathering and production of the Ore have been enhanced with modern techniques. From more efficient automated bellows to sifting methods for the collected sand using electromagnets to remove most of the impurities which would be present in purely traditional iron sand. And ofcourse the forging of the sword itself with electric hammers which also result in a way better quality sword, because of the consistency of the strikes. And that is not a bad thing. 3) "They are still considered to be among the best in the world." And this is: Inaccurate. Even in terms of Katana: Modern high-forged, mass-produced spring steel ones, will outperform traditional katana. 4) "One sword has been appraised at 105 million dollars, making it the most expensive sword ever produced" Appraisal price has nothing to do with how expensive a sword should be. That is rather missleading, because if someone were to appraise a sharpened butterknife at 106 million, that would not make it the most expensive sword. Because neither the labor cost nor the materials used justify that price. The reason it is valued that high is because of its representation of historical value, less to do with the sword itself and more the culture around it. 5) "Only steel made in this way (Tatara method) is used in the best japanese swords." Incorrect. As previously mentioned: Modern high-forged, mass-produced spring steel ones, will outperform traditional Tatara katana. They are however still amazing pieces of art, but calling it "the best japanese sword" is missleading. 6) "80% Pure Iron sand is an excelent source material for high quality steel" (Context: Compared to Iron Ore) Only if you, do not refine the Iron Ore further. As soon as you refine both the ore and the sand equally, you get much better Iron than what was produced from traditionally collected Iron Sand. 7) "The edge of these swords is much harder than it is in the west" That is: Accurate. And it offers one of the differentiating advantaged and disadvantages that I would have loved to hear here. Harder Steel is more brittle, but keeps it edge better. Making it exceptional agains cloth and layered soft armors or flesh. It cuts exceptionally well. The tradeoff is: Hard armor can shatter the blade more easily. Which is why as armor technology advanced: The blade became less and less relevant. Piercing weapons dominated. And spring steel is still hard enough to keep an edge exceptionally long, while being way more resistant to damage. _______________________________ To finish this off: This is not meant as a "european swords were better" style comment. The skill required to produce these Katana is amazing, the restrictions they had in terms of material led to techniques which compensated for a lot of it and the swords are indeed pieces of art which deserve admiration. I merely want to pushback against the missguided beliefs of the "Katana-Super-Sword" and the "Near-Perfect-Steel-Making" techniques that is widespread, even in this very comment section. QUOTES: "These swords are literally the physical embodiment of trial and error in a form that cannot be perfected further" "Katanas are just the best overall swords in the world." "It is amazing that they made the best steel to this day using only sand." There is value in keeping tradition, but these beliefs are objectively in error. Remember where you came from and embrace the lessons learned with modern tools. THAT is how you make the best product. Not overglorifying what was merely done out of nessecity.

[@roromad9603]

thank you. i love the artistry of japanese swords, but to think that the same quality isnt done elsewhere in the world is a very limited view of the world.

[@starogod]

@@roromad9603 Shad made alredy pretty good sumarisation of all mentioned "misinformations"

[@efgee]

I do love the Japanese katana, and it is my favourite sword, but yes, I have to agree that there are too many untrue myths surrounding the Katana. No one sword or sword types is the "best", it all depends on the many different elements of the combat environment and the sword user.

[@angamaitesangahyando685]

Immense gratitude! In a way, a conspirologist might even accuse Veritasium in promoting pseudo-science (remember the self-driving cars advertisement?). - Adûnâi

[@eagle162]

​@@starogodno he hasn't, shad is probably the worst historical KZbinr out there, he has given out inaccurate statements regarding Japanese swords and other weapons ignoring criticisms and disregarding corrections, including regarding European weapons not really discussing how many were actually made at the time but rather looking at modern recreations with better metal working. The majority of the historical community don't even like him and even actually historians are not fans. Here are some actual info regarding swords both Japanese and European. Neutron diffraction study on full-shape Japanese sword" The Investigation of Establishing Time of Zuku-Oshi and Kera-Oshi with Data of Iron Image of Buddha Making Age and Old Document "Kokon-Kajibiko" Ancient and historic steel in Japan, India and Europe, a non-invasive comparative study using thermal neutron diffraction, F.Grazzi et al, 2011. The Sword and the Crucible: A History of the Metallurgy of European Swords Up to the 16th Century, A. Williams, 2012 Some Aspects of the Metallurgy and Production of European Armor OCTOBER 18, 2016 Archaeometallurgical Investigation on Historical Sword-Making Techniques in Northern Italy Between the Sixteenth and Seventeenth Centuries, G.Tonelli et al, 2022 November 04, 2019 Japanese Swords "Mythbusting" - Part 1 La question du minerai de fer pour la période médiévale (IXe - XVIe siècle) Home-made steel: A week at Manabe Sumihira's zuku-oshi tatara Mineralogical Study of Iron Sand with Different Metallurgical Characteristic to Smelting with Use of Japanese Classic Iron-making Furnace “Tatara” Micromorphology, chemistry, and mineralogy of bog iron ores from Poland SOME THOUGHTS ON UTSURI Posted on 2013/08/22 January 27, 2019 Iron and Steel Technology in Japanese Arms & Armors - Part 3: Bladesmithing Also Gunsen History@gunsen_history. This person has actually made a few responses to him regarding his katanas videos.

[@VZAAGE]

This is one of the best channels on KZbin... and this is the coolest video shared so far.

[@Kanotoa]

Great video. I was familiar with the process of making katanas but this went more in depth. Great video, thank you!

[@stephano1221]

The village at <a href="#" class="seekto" data-time="284">4:44</a> is Shirakawa, which is the village that Hinamizawa - from Higurashi: When They Cry - is based on

[@RhynoD2]

Ah, good reason to NEVER GO THERE, then.

[@zerocool6452]

Oh wait you are right, how did I miss that?

[@gadnihasj]

So you're saying the village at death minutes, double death seconds..

[@2710cruiser]

Oh my… no wonder it feels familiar

[@crueltear]

@@RhynoD2You can go, but there is no return from the forest where cicadas cry.

[@Talik13]

This was beautiful to watch. I've played so many videogames with "smelting" and "forging" survival crafting - but I've never seen how it was done by hand. This was amazing.

[@badgermcbadger1968]

Tinkers construct

[@fireelighting8610]

Really shows the reality of the actual process, it ain't as easy as putting it in the crafting table

[@Yes-ux1ec]

Runescape

[@mati327]

Marvelous and detailed video... Superb work mate!!

[@GTJonas]

Fantastic video. I only wish it had been much longer. I could easily have watched it for an hour or longer. Impressively high production quality-as always.

[@HiGiBu]

couldnt unhear <a href="#" class="seekto" data-time="999">16:39</a> may thy blade chip and shatter

[@aussieglizzy6998]

You are deaf

[@samskordi6079]

Must be intentional!

[@anthonyserafini]

As it is writen

[@whereswilliam488]

As it was written

[@christo2333]

Thank you for this inside look at sword making. What a treat to see all this!

[@JW-dj7nf]

Thanks! GREAT job!

[@mphRagnarok]

May thy knife chip and shatter <a href="#" class="seekto" data-time="1000">16:40</a>

[@Kiesmander]

I'm incredibly impressed by the edge alignment on Petr's cuts on those tatami rolls. No scooping or anything.

[@vigilantcosmicpenguin8721]

I don't even know what edge alignment is and I'm still impressed by it.

[@pollianapavloski7911]

This was an incredible video, thank you.

[@datyeen]

"So sharp it can cut a bullet in half" Nearly every sword can cut a bullet in half.

[@gleniu2]

This. Overhyped a lot. Mass produced European swords had the same or better quality.

[@jez76]

You can cut a bullet in half with a Mora knife.

[@Theduckwebcomics]

True. Bullets are soft so any sword can cut one. Unless it's an armour piercing round, then that will break any sword. Katana have a harder than usual edge, which makes them more prone to breaking.

[@DarthRagnarok343]

I've seen a butter knife cut a bullet in half.

[@NONO-hz4vo]

@@gleniu2 It is classic Japan though. They will take something that is pretty ordinary and devout 100x hours to the process and make an art of it. It has it's pros and cons.

[@user-sc6bg3ky5t]

<a href="#" class="seekto" data-time="1376">22:56</a> it’s simply beautiful to see the awe and joy of the guy alongside the master’s clear proudness of his own work with that twinkle in his eyes

[@BabyMakR]

So lucky to have been able to witness that process.

[@jeremyroberts9938]

Great video! The care and dedication to the art form is un-real!

[@tsaqifrizky5276]

<a href="#" class="seekto" data-time="164">02:44</a> Ah yes, my "anti-bronze-sword" technique, I haven't used this since the Heian era

[@inactivefan]

Bro said “chip and shatter” and my brain was back in Dune mode so fast

[@McNuggetsOrElse]

As it was written

[@utkalsanjel2804]

Lisan Al-Gaib

[@rpandocchi]

This has been one of your best videos ever! Loved it!

[@danielso6589]

Just took my material science class this semester, you got no idea how happy i am when i understood everything regarding the microconstituents and phase change

[@pieterpennings9371]

“He fought 60 duels to the death, and won every last one of them”. Yea, otherwise he wouldn’t have gotten to 60

[@PlayerJ1]

lmao

[@sequoia7284]

If that wasn’t specified it would imply he lost the 60th.

[@pieterpennings9371]

@@sequoia7284 no because he says he retired after or something so he not ded

[@jtg1912]

Not every duel ends in death for the loser

[@sequoia7284]

@@jtg1912 every duel to the death does in fact end in death for someone.

[@cornellpidruchney1226]

Wow, GREAT VIDEO!!! I love your enthusiasm and wonder!!! Super interesting, thank you so much!!! 🎉😊

[@CloudWolfs]

Just the fact of trial and error and countless tests just to get the process right to where they are now even back then is absolutely mind blowing and incredible

[@WwarpfirewW]

<a href="#" class="seekto" data-time="1370">22:50</a> the master swordsmiths smile of satisfaction about perfect cuts done by foreigner with masterwork sword

[@Ready_Set_Boom]

I love how much the producer appreciated the craftsmanship and dedication of these artists.

[@fabiss23]

fantastic video. thank you!

[@fazpedeferro3066]

Até hoje foi a melhor explicação que já vi sobre algo.

[@lethalcuhh4820]

As a civil engineering student, your animations, live-steel production, and the well explained processes have taught me far more about the creation and forging of steel than the boring, crappy powerpoints shown at my uni.

[@TheMcFish]

That smile and the little nod from the master at <a href="#" class="seekto" data-time="1375">22:55</a> was golden

[@Razordreamz]

Probably my favorite episode! Very good thank you for this!

[@hardwarerepair200]

That's why I love Japan. The Japanese really perfect every technology imported to them.

[@alexanderren1097]

The statement at approx <a href="#" class="seekto" data-time="45">0:45</a> that the Japanese made a weapon that was the pinnacle for their style of warfare is incorrect if it refers to Katana since they were NOT primary battlefield weapons. If you want to talk about swords on Japanese battlefields then you need to look at Tachi, O-dachi, and other swords all of which were larger and more robust than katana. Even then, no sword was EVER the primary weapon that Samurai used on battlefields. Swords were always backup weapons or carried for self defense during unarmored “civilian” settings. The battlefield weapons of Samurai were bows/arrows, yari (spears), naginata (comparable to Chinese Guandao or European glaives), and guns. And yes, not only did Samurai use guns, they LOVED their guns once they found out about them from European traders and had bought enough to figure out how to make their own

[@TheGismono]

Makes sense, The 'Tachi' seams closer to that of the european 'Long Sword' in use cases. While the fighting style of 'O-dachi' would fill a same kind of roll as a 'Flamberge'.

[@dfriedbauer]

Ok nerd

[@yakfacethethird3054]

Absolutely. At most, the O-Katana was a battle-field weapon, but not the katana. The katana was more used for show, status, and sometimes duels.

[@the8thark]

The important part of that statement is "The materials they had at hand" The Japanese did not have perfectly clean iron ore to begin with. They also could not make pure steel because the bloomery furnace did not liquify the iron. Only the outer slag/impurities were removed. The slag/impurities on the inside of the iron ore stayed. This is exactly why they folded the steel. It was the best compromise. Can't remove all the impurities, so lets fold the steel so the entire blade is uniformly impure, not perfect in some spots and super impure in other spots. You are not incorrect in what you say. I agree with you. However as a secondary battlefield weapon (not primary like the yari or guns) and based on the materials they had at hand the katana was the best they could make. Also around the 1500's the Japanese used the older Tachi and the newer uchigatana. Uchigatana means strike sword. Around the late 1500's the Tachi went out of fashion and the uchigatana was then just known as Katana. Katana just means sword. There was no longer two different backup weapon swords being used so no need to differentiate them. At that point when everyone is using a striking sword, no need to call it striking sword, so peopel just called it a sword (Katana).

[@RealZeratul]

@@dfriedbauer why would one watch Veritasium documentaries and at the same time write comments downplaying the value of well-written comments such as OP's, which provide corrections and extra info to everybody interested in it?

[@nickverbree]

The crystal structure animations in this were awesome and I've shared this to a bunch of smiths who I've struggled to get the idea across to. Brilliant work, and a great watch.

[@Amino_Domado]

I'm so HAPPY that Miyamoto Musashi is mentioned in this video!!! I was expecting it because you love to add some historical background in your videos.

[@funmaster5249]

Thank you for this.

[@link6913]

Another banger. Shoutout to Petr for his hard work on this one. You can tell hit put his whole heart into it.

[@kricku]

<a href="#" class="seekto" data-time="1163">19:23</a> You know the reference

[@darkkingshocker]

Overdrive

[@BusterNoggins]

A full video of this would be awesome.

[@maniarasan6720]

Thank you for this video

[@mu11668B]

I remember as a kid I had access to some educational DVDs produced by NHK. All the videos were live demos of physics and chemistry experiments. One of the experiments talking about redox was this kind of iron smelting procedure. It wasn't as high-tier like this one and the "kiln" was just a tower of cinder blocks. This videos just brought back my memories watching those quality contents.

[@rudijohnsen9674]

When you were partying, I studied the blade. While you indulged in the latest binge-watch, I mastered the ancient techniques of sword-forging. As you scrolled endlessly, seeking validation through likes and follows, I cultivated patience and precision in the heat of the forge. Now, as the world marvels at the artistry of the Japanese sword, and collectors clamor for a piece of history, you have the audacity to ask me to share the secrets of the katana. Remember, while you chased fleeting pleasures, I embraced the discipline of the blade.

[@peterobinson3678]

Ok, boomer...🤔😂

[@df71091]

Tldr

[@kennethn3179]

Wtf? 😂🤣

[@ELYESSS]

When you were partying, I studied the blade. While you indulged in the latest binge-watch, I mastered the ancient techniques of sword-forging. As you scrolled endlessly, seeking validation through likes and follows, I cultivated patience and precision in the heat of the forge. Now, as the world marvels at the artistry of the Japanese sword, and collectors clamor for a piece of history, you have the audacity to ask me to share the secrets of the katana. Remember, while you chased fleeting pleasures, I embraced the discipline of the blade.

[@life-destiny1196]

Y'all wouldn't know a pasta if someone served it to you in some fancy restaurant

[@tomburnip7565]

Truly amazing video. Great stuff.

[@Minalien]

<a href="#" class="seekto" data-time="423">7:03</a> "Things are very much getting real" C'mon "things are heating up" was RIGHT THERE 😭

[@infinite540]

Wow this was awesome. More swords with metallurgy please!

[@Enyzlac]

Agreed with one of you last statements beautiful pieces of art! ❤

[@Bokilano]

Wow. Everything is “handmade” except the bellows and that giant hammer and look at that crane. What an amazing purely “handmade” process. Definitely everything is done by hand and I mean by “hand.”

[@RedIsntHome]

<a href="#" class="seekto" data-time="165">2:45</a> They probably made them to use against Sukuna

[@DavidWhoHasBeenSaved]

😎

[@AndrewRoberts11]

FYI: We know approximately when bronze casting began, circa 4650 BC, when some chaps, in present day Serbia, stumbled across Stannite Ore (a natural ore that contains cooper, tin, and iron), and started to leave the artefacts behind. A Katana is an efficient cutting, rather than stabbing, blade. Cutting blades are a periodic fashion, in the West, they disappear when chainmail or plate armour are in common use, say in the Classical period (500 BC - 500 AD), or High Medieval (1000-1500 AD), and reappear then the majority of opponents will be protected by textiles (So rather than Rock-Paper-Scissors, think cutting-armour-stab).