How should I care for a full-tang carbon steel chokuto?
Updated Mar 2026
Carbon steel chokuto blades require periodic maintenance to prevent surface oxidation, especially in humid climates. Apply a thin, even coat of choji oil or a neutral mineral oil every three to six months using a soft cotton cloth - avoid touching the blade surface with bare hands, as skin oils accelerate rust formation. Store the sword horizontally in its saya with the edge facing upward. Keep the piece away from direct sunlight, which fades lacquer on the saya, and away from heating vents or air conditioning units, which create humidity swings that stress both the steel and the organic mount materials. A display case with UV-filtering glass and humidity maintained between 45-55% RH is the ideal long-term environment.