: They were crafted using crucible steel , a high-purity metal with a carbon content so high that the technology to create it wasn't thought to exist in Europe until the Industrial Revolution.
: It has been used to describe Sephiroth's Masamune in various media, highlighting its supernatural length and power. The Sword That Shouldn't Exist
: On collector forums like the Nihonto Message Board , it is often used for modern Chinese fakes that mimic Japanese signatures but lack the correct historical construction. : They were crafted using crucible steel ,