How Japanese Masters Turn Sand Into Swords

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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:

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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

[mackerel]

man open youtube, man see sword, man happy

[toshiyukisaito]

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.

[XYZ-lmtp]

I thought it would be a random video of forging a sword, but bro taught us whole chemistry, geology, and history behind it

[uhgcvkt]

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.

[AAbattery]

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.

[shangerdanger]

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

[JackSparrow-sttg]

He explains the physics so well I even enjoyed the razor ad at the end.

The swords were obviously beautiful. The shear dedication, focus, love and genuine respect with which they are crafted inspires me.

[abbasduman]

I find it so amazing how Japanese people still keep their art and traditions alive. The mastery is unbelivably beautiful.

[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.

[shangerdanger]

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

[naxy]

23:38
by bowing that low you showed deep respect for that man, I appreciate you exploring and understanding the culture of Japan, as well as taking the time to understand and enlighten the internet about Japanese craftsman ship, I myself am not Japanese, but have a deep respect and admiration for their culture and it makes me happy to see light being shed on their amazing traditions and country.

[kaalen]

Imagine crafting a sword that survives combat and gets passed down dozens of generations of family and is still around in 2024 when it was constructed in the 1600's. Not only that, its still beautiful to behold. Simply masterful.

[azndude]

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!

[Thesupperals]

"Whatever you do, you should do it deep care, with attention to detail, and love for the craft." That explains why so many under paid karoshi happen to be found in the animation studios.

[kawaranai]

22:55 the swordsmith is actually impressed by mr. producer's cut

[neophoys]

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.

[kylejohnson]

Japanese craftsmanship can be defined by one word: patience.

[smittywerbenjaegermanjense]

There’s only a few things I will never get tired of watching over and over again on YouTube, and the making of a traditional Japanese Katana is one of them.

[arsumbris]

That's incredible. Those artisans are amazing, I admire them. Very gracious of them to include you.

[konstantinospalapanidis]

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