Testing Tamahagane - Traditional Japanese Steel Media

I got some Tamahagane to test in Japan and compared it to modern steels for toughness and edge retention. How did it compare?

Life Where I’m From video on making Tamahagane: https://youtu.be/95ZT_opuaSA

Written article: https://knifesteelnerds.com/2025/09/10/testing-tamahagane-traditional-japanese-steel/

00:00 Intro
00:10 Making Tamahagane
02:39 But what is it?
05:10 Hardness distribution
07:07 Forge Folding and Inclusions
10:33 Mechanical Properties in Literature
13:00 Carbon Content
15:51 New Tamahagane Tests - Carbon
18:01 New Tests - Microstructure
18:56 New Tests - Inclusions
20:05 New Tests - Hardness
21:26 New Tests - Toughness
22:16 New Tests - Edge Retention
23:40 Summary