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 https://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.

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CORRECTION: There's a typo at 18:20. The combination of Ferrite and Cementite is Pearlite, not Perlite. Thanks, @neophoys for pointing it out.

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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 https://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 – https://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 – https://ve42.co/NHK



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Directed by Petr Lebedev
Written by Petr Lebedev and Derek Muller
Edited by Trenton Oliver and Jack Saxon
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