What care does a display tachi need to stay in top condition?
Updated Mar 2026
High-carbon T10 steel is not stainless and will oxidize if neglected. For display pieces, the single most important maintenance habit is periodic oiling: a light application of choji oil or mineral oil along the entire blade surface, wiped to a thin even coat, creates a barrier against moisture. The frequency depends on your environment - humid coastal climates may require attention every four to six weeks, while dry inland conditions might allow three months between applications. Always handle the blade with clean cotton gloves or by the spine to avoid transferring skin oils, which are mildly acidic and can leave fingerprint marks that etch into the steel over time. Lacquered saya should be stored away from direct sunlight, which can crack or fade the finish, and the blade should be withdrawn periodically to ensure no moisture is trapped inside the saya against the blade surface.