3. Older Katana’s Were The Best
Although the official sword testing department wasn’t created until the early 17th century, the blades made before 1530 were of exceptional caliber when compared to blades made later. Supposedly, when a 16th-century blade was officially tested at the department, it was said to have cut right through seven bodies with a single slice.
The reason for the degradation in blades has mainly to do with the introduction of European guns to Japan in the 1540s. Having an abundance of easy-to-use, highly effective weapons meant that the sword makers no longer needed to produce katanas of the same quality they once did. Consequently, many of the techniques that were once used to forge a first-rate blade were lost. And, as the quality of and need for blades declined, so too did the samurai’s ability to assess them. This led to some smiths focusing more on elaborate designs rather than a sword’s cutting power. Eventually, this watered down method of sword making became so prevalent that the old method for making katanas became all but extinct.
http://www.bugei.com/skyjiro-swords-168-ctg.htm Via bugei.com
2. High Quality Katana’s Eventually Made a Comeback
Following World War II, the American occupation force in Japan strictly outlawed the manufacture and possession of swords until 1953. When the prohibition was lifted, there seemed to be a renewed interest in katanas that brought about the formation of the Society for the Preservation of the Japanese Sword. This organization was dedicated to resurrecting the ancient techniques and methods required for making the coveted tamahagane steel used in the authentic old-world blades.
Now, a licensed smith in modern Japan must craft blades in very much the same way that it was done centuries ago. And thanks to the Society for the Preservation of the Japanese Sword, there are strict guidelines on the creation of blades to ensure that modern Japanese katana’s are of the highest quality –equal to, if not greater than, those forged in the 16th century.
https://en.wikipedia.org/wiki/Katana Via Wikipedia