What is Sori(反り)?
- Sori means the curvature of the sword.
- The origin of Sori dates back to Heian period when TACHI(太刀) was developed. Before then, all Japanese swords were straight.
- Where and how much the deepest point of the curve is an important factor in sword appraisal. Because it gives you the idea of how old the sword is and who made it.
- Koshi-Sori(腰反り) : The deepest point of the curve is near NAKAGO(茎). Common from the late Heian to early Kamakura period.
- Naka-Sori(中反り) : Known as Torii-zori(鳥居反り) also, the deepest point is at the center of the blade. Common during Kamakura period.
- Saki-Sori(先反り) : The deepest point is above the center of the blade. Common from Muromachi to Sengoku.
- Uchi-Sori(内反り) : The curve goes toward the edge. Common in only TANTO (短刀).