How does a bo-hi (groove) affect the blade?
This question has come under debate recently, however we believe a blade groove works like an I-beam, giving lightness with only a minimal sacrifice of strength. It also produces some drag causing a “swoosh” as the blade swings called tachi-kaze (sword wind). Q: What is the best type of edge for a Japanese sword? A: The best edge depends on the application of the sword. A stone polished edge that is slightly but not overly convex is ideal for most circumstances. This allows the blade to be sharpened to a fine edge at the same time placing the most possible material to support it. How dramatically this shape is expressed varies by the intended target; to cut through heavy armor or bone, a heftier blade with a more convex edge is used. When quickness and soft-target cutting ability are emphasized, lighter blades with smaller profiles are chosen as they give less resistance and are more easily wielded. Competition blades strive to be as thin and wide as possible to minimize resistance aga
