man open youtube, man see sword, man happy

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

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

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

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.

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.

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!

As an amateur American blacksmith, I truly appreciate you making this video. The history and techniques of Japanese sword making is fascinating and should be understood by anyone that wants to learn blacksmithing. Thanks again! Great video!

18:20 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.

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.

We owe it to these Japanese craftsman. No modern science. Just skill practice and repetition. Absolutely beautiful

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!

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

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.

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

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

For that price it better be brimming with haki.

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.

i have seen plenty of sword/ katana making videos... this is the best one ive ever seen in my entire life. great job!! thank you.❤❤❤

"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

I've seen only a few really good documentaries about katakana in English. This is the best I've seen at explaining the material science. Very well done. Thank you!

Very cool and educational. The explanation of quenching and carbon atoms was fantastic. I have such a better understanding of its function now. Before, all I knew was slow quench is softer and fast quench harder but did not know why. I can better appreciate why these cost so much now, particularly the ones made before electric bellows and mechanically driven hammers. Many thanks to those who let you film this!

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.

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 👏 👌

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

23:38 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 😭

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

Truly amazing. Thank you for sharing this experience.

Japanese craftsmanship can be defined by one word: patience.

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.

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.

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!;

Truly a fantastic video. I’ve already forwarded it to multiple people.tyvm

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.

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

This is like, the Demon Slayer sword making place.

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

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

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

Just wow.. properly the best video i have seen on Japanese sword craft from the perspective of a western journalist.

I read an article about these swords in Machine Design magazine. The most important detail is not “the” alloy used, but a combination of TWO steels, that are layered by folding so that a very hard alloy forms the edge, and a softer, more flexible alloy prevents the sword from shattering. Whoever independently discovered this process was a genius.

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

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.

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

Great video! Very in depth thank you for sharing this

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.

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

Loved the science explanation and history explanation through it all, learnt alot through this thankyou

Nice video and such a valuable message in the end ... Good work team for exploring the beautiful art in Japan

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.

2:47 Ah yes the bronze katana technique I haven’t had to use this since the heian era

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

Every trade is from deep down professionalism Great video and much respect

The statement at approx 0:45 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

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.

Honestly, your channel teach me more about anything and in a much better way than school

What an incredible experience. Learned a lot from this video.

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

Everything Japan makes is done with great skill. I have seen so many videos of items from swords to wood furniture and Everything seems to be done with such amazing skill and attention to detail and the end results are always nothing short of amazing. Very smart skilled craftsmanship.

19:35 clay is watered down into a paint and artists use a brush to paint on layers to achieve the high level of detail in the Hamon in addition to the process of wrapping thicker layers of clay. Though if you are referring to the blade thought to be made by Sukekane, the dragon is simply engraved and not from using clay and quenching. Incredible video by the V team.

19:23 You know the reference

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.

This was a very well made and interesting video. Excellent editing and narration. Japanese swords have always fascinated me and tis video explained the making of them very well. Thank you!

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

The village at 4:44 is Shirakawa, which is the village that Hinamizawa - from Higurashi: When They Cry - is based on

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.

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

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

May thy knife chip and shatter 16:40

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

Beautiful video and i really appreciate your respect for the art.

2:45 They probably made them to use against Sukuna

couldnt unhear 16:39 may thy blade chip and shatter

If you can find a Hattori Hanzo for under a million you should buy it for sure.

Excellent videos! Nice narration, scientific analysis, culture background! Congratulations!

02:44 Ah yes, my "anti-bronze-sword" technique, I haven't used this since the Heian era

This is wonderful, Thank You!

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

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

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

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

This is amazing. Thank you.

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.

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

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.

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

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.

22:56 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

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

Thanks! GREAT job!

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

This is why i fell in love with Japanese kitchen knives when i visited Japan. Many of the old sword making families transitioned to kitchen knives after sword making became less common and they still use the same techniques of forge-welding different types of steel today. Every piece is a unique and highly functional work of art

16:35 As it was written.

Metal smelting and forging taken to high art, true craftsmen of exceptional skill.

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.

19:24 it's that a jojo reference? 🤨

I've seen numerous documentaries on Japanese swordsmithing. I could watch a thousand more. So glad one of my favorite science channels decided to tackle the subject.

As a mechanical engineering student, i can say that the metallurgy and material science concepts explained in this video in such simple manner, its gold...

Experiencing all of this through Peters eyes is such a cool addition. The facts are interesting, but all the emotions gave it another dimention. I love it!

I don't know why I am in tears after watching this video. The art of making Katana is beautiful beyond any justifiable explanation.