Seiko Crown – Balance Staff Stud Screw (ヒゲ持ネジ) – Part No. 022150 – NOS Watch Part – (1 Piece)

Original Seiko hairspring stud screw from new old stock (NOS), part no. 022150, for the Seiko Crown model (Jap. ヒゲ持ネジ「クラウン」, hige-mochi neji = hairspring stud screw).

This small screw secures the hairspring stud (the holder for the outer end of the hairspring) – a functional original part that is often damaged or lost in vintage movements and is needed for the professional restoration of a Seiko Crown.

Historical Background – Crown and Grand Seiko: The Seiko Crown was introduced in 1959 by Suwa Seikosha and was based on the Marvel/Lord Marvel, but brought profound technical advances: the Caliber 560 with a larger balance wheel (better isochronism), a larger mainspring barrel, and improved Diashock shock protection. It was precisely this foundation that led to the birth of the first Grand Seiko (1960, Caliber 3180) a year later – Japan's first watch to meet the testing criteria of the Bureaux Officiels de Contrôle de la Marche des Montres. The Crown is thus the direct technical link to the Grand Seiko line and a historically significant model for any serious Seiko collector.

The part comes from an original Seiko factory bag (Part No. 022150). The price is per piece.

Technical Data:

• Manufacturer: Seiko (original Japanese factory packaging)
• Part: Hairspring stud screw (ヒゲ持ネジ)
• Part no.: 022150
• Model assignment: Seiko Crown
• Condition: NOS – unused, from opened original bag
• Origin: Japan

Note Unused original part from old stock; the original bag is opened and may show slight signs of storage and age. Please verify the exact caliber/model assignment (Crown series) against the specific movement before installation.