Samurai Sword

In this video we learn that the ancient world had a very good notion on how to make high quality, strong steel in fashion that could be done 1000s of yrs ago. Charcoal and iron rich sand, mud bricks and fire are all that is required. While my other video on this subject is more focused on the steel itself, this one has a better detail of how a Katana is made, while manages to be quite good at explaining the furnace that allows the creation of the carbon steel.