 In this video they have a katana setup in a vice and a k9mm pistol setup in a gun vice device with the 9mm pointed at the blade of the katana. The blade is edge on to oncoming the bullet. The guy presses a lever on the gun vice which pulls the trigger on the 9mm (I assume this is so that they have it exactly correct to hit the edge of the katana). The bullet hits the edge of the katana and splits in half; hitting the target behind the katana in two pieces. They show a closeup of the katana blade after the bullet hits it and as far as I can tell there is metal from the bullet stuck to the blade. I don't think the blade was damaged by the bullet.
Watch the full video of this 9mm bullet hitting a katana below or click over and view it on the host site. Source: Google Video | 
