Japanese Sword Terminology

• Boshi The hardened edge (yakiba) as it extends past the yokote into the kissaki.
• Ha The sharp edge of the blade.
• Habuchi The transition zone from soft to hard steel (defines the hamon)
• Hada The kind grain pattern of the blade
• Ha-machi Notch on ha side of blade
• Hamon Pattern of the differentially hardened edge.
• Hi Groove used to improve balance by lightening blade while retaining stiffness.
• Hira The surface from ha to shinogi
• Ji-gane The surface between the hamon and shinogi
• Ji-hada The surface grain of the metal formed by repeated forge folding.
• Kata-haba Width at widest point.
• Kissaki Tip region
• Kizu Flaws in the blade.
• Mei Signature or inscription on tang.
• Mekugi-ana Holes for mekugi to pass through and attach blade to tsuka.
• Mune The back of the blade.
• Mune-machi Notch on mune side of blade. The habaki presses up against these.
• Nagasa Length of the blade measured from munemachi to kissaki
• Nakago Tang of blade
• Nie Larger crystals of martensite
• Nioi Small crystals of hardened steel (martensite).
• Omote Exposed side of sword (as shown here).
• Saki-haba Width at yokote
• Shinogi Ridge line along side of the blade
• Shinogi-ji Surface between shinogi and mune
• Sori Depth of curvature, measured from a line between munemachi and kissaki.
• Ura Hidden side of sword
• Yakiba Hardened area of the blade.
• Yasurime File marks on nakago.
• Yokote Ridge line dividing kissaki from the rest of the blade