Winding Stem suitable for Seiko – Size 10½''' – Vintage Men's Hand-Wound Watch – (1 piece) – NOS

Winding stem (巻真) from new old stock (NOS), manufactured to fit Seiko movements of size 10½ ligne. A single piece is offered, taken from an original supplier package with the imprint "FOR SEIKO WINDING STEMS" and the size stamp 10½.

Regarding origin: This is a spare part from a Japanese supplier, intended for Seiko movements – not an original part distributed by Seiko itself. Such supplier stems were common practice in Japanese watchmaker workshops in the post-war decades and were matched in quality and fit to the production movements.

The size indication in lignes (10½''' corresponds to approx. 23.7 mm movement diameter) instead of caliber numbers refers to the period before the introduction of Seiko's numerical caliber designation, essentially the 1950s. 10½''' is the classic men's watch size of this era; accordingly, the stem is suitable for hand-wound movements from the early phase of industrial Seiko wristwatch production.

The winding stem transmits power from the crown to the winding wheel and, via the setting lever detent, controls the change between winding and hand-setting positions. It is one of the components most directly stressed in everyday use: a torn thread – a typical consequence of a forcefully pulled winding crown – or a worn square renders an otherwise intact movement useless. For movements of this age, replacements are practically only available from old stock or donor movements.

Size indication on package: 10½''' (lignes) - 「新10½」 – "new/new type, size 10½ lignes"

The part is unused. Due to storage, slight, purely cosmetic traces may be present, which do not affect functionality.

Note on attribution: The size information comes from the original packaging; a caliber-specific attribution is not documented. Only the dimensions mentioned above are decisive. Please compare these with the required winding stem before purchase.

Origin: Japanese supplier part, manufactured for Seiko watch movements. The brand SEIKO is used solely as an indication of purpose; the part does not originate from the Seiko Watch Corporation.

Warranty (used)
This is a spare part from old stock (NOS) stored for decades. The limitation period for warranty claims (statutory warranty) is 12 months from delivery.

Note
Before installation, please compare the stem dimensions and fit with the required winding stem; assembly should be carried out professionally.