Can a Rusted or Poor-Condition Japanese Sword Sell? Why You Must Not Polish It Yourself

If an inherited Japanese sword is rusted or in poor condition, it is tempting to think "it must be worthless now" or "let me remove the rust myself and clean it up." But that self-judgment can greatly harm the sword's value. Here we organize how to handle a sword in poor condition.

Rusted Does Not Necessarily Mean "Unsellable"

A sword's value is not decided by condition alone. Who made it (the smith), its period, rarity, and whether it is signed greatly affect value. Even under the NBTHK's screening standards, a sword that is unsigned but whose period/province/lineage can be identified, or that has some fatigue or flaws yet still bears appreciation, can qualify as Hozon Token. In other words, "rusted" does not equal "worthless." Rather than deciding on your own to discard or neglect it, have a specialist look at it first. (That said, deep flaws or defects that greatly spoil the appearance do affect the assessment, so condition is one factor in value.)

Never Do This — Removing Rust, Polishing, or Grinding It Yourself

Never rub the blade with sandpaper, metal polish, files, scrapers, or coins. These damage the blade and destroy its value as an art object irreversibly. The NBTHK states plainly, "should a sword rust, do not attempt amateur care — consult a polisher (togishi)." Polishing itself reduces the blade's thickness (kasane) and can, in some cases, lower value.

Polishing and Rust Treatment Are the Professional Polisher's Work

Polishing and rust treatment are the work of a specialist called a togishi (polisher). Sword polishing is designated an Important Intangible Cultural Property and is a highly advanced craft that has produced Living National Treasures. The NBTHK puts it as, "when a sword rusts, [go to] a trusted polisher." If you are concerned about condition, consult a trusted togishi rather than improvising.

Polishing Is Expensive and Slow — Should You Polish Before Selling?

Polishing is charged per sun (about 3 cm), so even a standard sword adds up to a considerable amount, and turnaround can range from tens of days to, in some cases, more than half a year (amounts and timelines vary greatly by polisher and by the sword's condition). For a sword that is not highly valuable,