The tachi predates the katana by several centuries and differs in three measurable ways. First, its nagasa (blade length) typically exceeds 70 cm, making it noticeably longer than a standard katana. Second, its sori (curvature) is deeper and positioned closer to the base of the blade rather than the center, giving it a more pronounced arc when viewed in profile. Third, and most visually striking for display purposes, the tachi was worn suspended edge-downward from the belt — the opposite of the katana's thrust-through-obi carry. This edge-down orientation is the historically correct way to display a tachi on a stand, and it changes the entire visual balance of the piece compared to how a katana would be presented.