Patek Philippe 12-120

The 12'' 120 calibre was originally designed with a flat hairspring and was greately modified when the Breguet hairspring was fitted into the movement. The following parts were affected by this alteration: barrel arbor, balance, click, crown wheel core, crown wheel, balance endpiece (lower), train jewels, ratchet wheel, centre wheel, canon pinion and third wheel.

Serial no´s:

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  826.892 - 829.999: Balance with screws, Diameter: 10.60 mm, Flat hairspring.
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  920.000 - 920.991: Balance with screws, Diameter: 10.70 mm, Breguet hairspring.
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  920.992 - 928.147: Balance with screws, Diameter: 10.85 mm, Breguet hairspring.
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  928.148 - FF : Balance with screws, Diameter: 11.20 mm, Breguet hairspring.
• 
  960.000 - 969.999: Balance with screws, Diameter: 11.20 mm, Breguet hairspring.

Data Patek Philippe cal: 12'' 120

• 
  18 jewels, manual wind, hour minute and sub second display.
• 
  S: = 26.75 mm.
• 
  H: = 4.00 mm.
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  N: = 18.000 A/h.
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  Power reserve:
• 
  Mainspring: Height: 1.42 mm, Length: 363 mm, Thickness: 0113 mm.

Versions:

• 
  12'' SC: Sweep second. No´s: 861-704 - 864.271. Based on 12'' 120, most parts incommon.