What is Oowazamono in Japanese Katana terminology?

"Oowazamono" (大業物) refers to a category of Japanese swords known for their exceptional sharpness. This classification was established by two professional sword testers, ""Yamada Asaemon Yoshimutsu"" (山田浅右衛門吉睦) and ""Sudou Godayuu Mutsuzumi"" (須藤五太夫睦済). They divided the swords into four grades based on the results of their cutting tests: ""Saijou Oowazamono"" (最上大業物), ""Oowazamono"" (大業物), ""Yoki Wazamono"" (良業物), and ""Wazamono"" (業物).

Among these, ""Oowazamono"" is the second highest grade. Swords in this category are recognized for their superior cutting ability, making them highly valued by samurai and sword enthusiasts alike. The sharpness of these swords is not only a testament to the skill of the swordsmith, but also a crucial factor in their effectiveness in combat."