How do I properly care for and maintain an authentic Japanese katana sword over the long term?
Updated Feb 2026
Maintenance is straightforward but should be done consistently. The most important task is keeping the blade dry and lightly oiled. After any handling, the oils from your skin can cause spotting on carbon steel, so wipe the blade with a soft cloth before storing. Every few months - or after any extended display period - apply a thin coat of choji oil using a soft cloth or the traditional uchiko powder ball method. Spread the oil in thin, even strokes from base to tip, always moving in the same direction. Store the katana horizontally in its saya, edge up, on a proper sword stand. Avoid areas with high humidity or dramatic temperature swings, as these accelerate both rust and damage to the wooden fittings. Never store the blade without its saya or lean it against a wall without proper support. With this level of care, a well-made katana can be maintained in excellent condition for decades and passed on to the next generation in the same state.