Citizen PHINOX Mainspring – NOS Original Mainspring for Citizen · Size 5 · 1.35 × 0.0825 × 215 mm · 1 piece (NOS)

NOS mainspring from original Citizen workshop stock, series "PHINOX - Citizen" with the classic Citizen "C" logo. Offered is a single piece (1 piece) from an original dozen box ("1 Dozen").

This spring is intended as a historically correct original replacement for vintage Citizen movements and is ideal for restoration and service.

Technical specifications (manufacturer's information on the box, "品質規格" = quality specification):

• Brand/Series: Citizen PHINOX
• Purpose: for Citizen
• Size: 5
• Thickness (厚さ): 0.0825 mm
• Width (幅): 1.350 mm
• Length (長さ): 215 mm
• Original box content: 1 dozen (here sold per piece)

About the brand / material:
The box bears the designation "PHINOX" – a spelling variation of the spring material "Phynox" that Citizen used in this series (a sister box of the same design is labeled "PHYNOX"). Both refer to the same high-quality cobalt-chromium-nickel alloy (Co-Cr-Ni). This cobalt-chromium-nickel alloy offers a combination of high strength, ductility, and good mechanical properties, is hardenable, has excellent fatigue strength, is corrosion-resistant, and non-magnetic. Phynox is also known under the names Elgiloy, Conichrome, and Alloy 3J21.

This makes this spring part of the category of modern "white metal" springs, which, unlike classic blue carbon steel, are stainless, virtually unbreakable, and retain their elasticity. Citizen marketed its original mainsprings – similar to Swiss manufacturers with "Nivaflex" – consciously under the premium alloy name. It is therefore a Citizen original part. The nostalgic box graphics also make the piece a decorative collector's item from the heyday of the Japanese watch industry.

Scope of delivery:
1 piece mainspring "Citizen PHINOX" (single piece from original box). Photo shows representative box, specification label, and sample spring; a single spring of the specified dimensions will be delivered.

Warranty (used)
This is used goods (New Old Stock from old inventory). The statutory warranty is shortened to 12 months.

Note
Due to its age, no guarantee is given for the function or the unused elasticity of the spring.