The katana is considered on of the greatest swords ever created. Originating in Japan, the katana was the primary weapon of the samurai. Katanas are constructed using iron sand, which when turned into steel creates a metal of incredibly high purity. After the metal is made it is then worked and folded one thousand times, creating a highly durable blade. contrary to popular belief, the blood groove commonly found on the spine of the blade is not for blood. The groove simply adds strength and flexibility to the weapon to reduce the risk of breaking. The katana was such an effective weapon that it was used by the Japanese until the end of WWII. Proper technique for using a katana is to grasp the handle firmly with both hands and strike with quick, sharp, and short slashes.