OH済 is a Japanese listing notation meaning "overhaul completed." When a seller writes OH済 in a listing, they are disclosing that the watch movement has been professionally disassembled, cleaned, lubricated, regulated, and reassembled, typically with new gaskets and worn components replaced. It is one of the clearest positive condition signals in JDM watch listings.
Context and Usage
OH stands for オーバーホール, the Japanese phonetic rendering of "overhaul." The 済 suffix means "completed" or "already done," a pattern you will see across several Japanese listing terms. A watch described as OH済 should have had its movement components ultrasonically cleaned, dried, lubricated with spec-appropriate oils, and re-regulated for accuracy. In Japan's secondhand watch culture, where seller disclosure norms are unusually high, OH済 carries real weight.
Two related terms signal the opposite condition. 要OH means "overhaul required," which signals the seller is telling you the watch needs service. 整備済 means "maintained" or "serviced" and is a slightly broader term that can include external work like polishing or bracelet adjustment in addition to movement service.
Do not confuse OH済 with 動作確認済 (operation confirmed). A watch can be running and confirmed as such without ever having been overhauled. OH済 is a higher bar.
Why It Matters for JDM Buyers
Service intervals for modern mechanical Seiko movements run 4 to 6 years under normal wearing conditions. For a SARB033 or SARB035 that was manufactured between 2003 and 2019 and may have sat in a Japanese closet for years, a recent OH済 from a reputable watchmaker can mean the difference between a watch that tracks within 15 seconds per day and one that gains two minutes.
OH済 listings command a premium, often 10 to 20 percent above otherwise identical unserviced examples. For vintage Seiko divers such as the 6309-7040 and 6105-8119, that premium can be larger because the service cost itself is significant.
The caveat: OH済 is a seller claim, not a verified certification. Reputable Japanese sellers on Yahoo Auctions frequently include the watchmaker's receipt or a service date in the listing photos. If a listing claims OH済 but shows no documentation and was listed by a private individual rather than a watch shop, treat it as unverified. A watch shop (時計店) with professional credentials listing OH済 is more reliable than a private seller using the same term casually.
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