Traditional katanas are made of steel folded one thousand times.
the verdict
SUPPORTED
the evidence backs this
confidence 81/100
Traditional Japanese katanas are indeed manufactured using a labor-intensive process of repeatedly forging and folding tamahagane steel to refine its microstructure and manage carbon distribution.
Evidence for · 2
Microstructural Observation on Materials of the Japanese Sword under Fold-Forging Process
2010 · cited by 7
The study investigates the microstructural development of Japanese swords under the traditional forge-fold operation using tamahagane steel.
See more details
More for · 1
Traditional Japanese Sword Making from a Tatara Ingot As Estimated from Microstructural Examination
2004 · cited by 7
The research confirms that traditional Japanese sword-making involves repeated cycles of forging and folding to homogenize the heterogeneous tatara ingot.