The shinogi is a prominent ridge that runs the length of the blade of a katana. It separates the flat sides of the blade, or hira, from the cutting edge and helps to strengthen the blade by distributing force and absorbing shock.
The shinogi is one of the characteristics of the katana, as it distinguishes it from other types of swords. The width and height of the shinogi can vary depending on the design of the sword and the preference of the swordsman. A well-defined and straight shinogi is considered a sign of a well-made katana.
The shinogi-ji is the area between the shinogi and the edge of the blade. It is usually a flat, highly polished surface that can be decorated with different types of patterns, such as waves, wood grain or clouds. The shinogi-ji is an important part of the sword’s aesthetics, as it allows the swordsman to showcase his artistic skills.
The shinogi and shinogi-ji are important elements in the construction of the katana, as they help to create a strong, durable, and combat effective blade. A well made shinogi and shinogi-ji can enhance the beauty and effectiveness of a katana, making it a valuable item for collectors and enthusiasts.