How should I store and maintain a carbon steel katana long-term?
Updated Feb 2026
Carbon steel requires consistent maintenance to prevent oxidation. After each handling session, wipe the blade with a clean soft cloth to remove fingerprint oils, then apply a very light coat of choji oil (traditional clove-infused mineral oil) or plain food-grade mineral oil along the entire blade surface. Store the katana horizontally in its saya with the edge facing upward — this is the traditional Japanese orientation and prevents the edge from pressing against the saya liner. Keep the sword in a room with stable, low humidity; avoid basements, garages, or rooms with wide temperature swings. Inspect the mekugi peg annually and replace it if it shows cracking. For display pieces stored on an open stand, a monthly light re-oiling is advisable, as air circulation accelerates the evaporation of the protective oil layer.