PLEASE stop this shit: BE HAPPY that katana is useable AT ALL:
KATANA: last chance, desperation weapon for a samurai who has been behorsed and disarmed. Not a frontline weapon, ever. Even the japanese KNEW it was NOT a weapon for battle. It is made from bad quality steel, and serves best at slashing unarmed opponents. More of a testament to the noble birth of its carrier than a weapon, the design stayed the same for nearly a thousand years because it is aesthetically pleasing.
The larger bastard swords and the longsword: Technology 500 years in advance of katana, used as a mainline weapon, under constant development and improvement and made from vastly superior steel. No offence to the japanese: you cannot blame them for the natural resources they DIDN'T have.