The AS 1187/94 is a vintage Swiss mechanical watch movement made by A. Schild SA, featuring manual winding and a sweep second hand. Introduced in the 1940s, it served as a reliable workhorse ébauche utilized across numerous mid-century watch brands, including periodic use by Tudor. [ 1 , 2, 3 , 4 ]
**Technical Overview **
- Type: Mechanical manual-wind
- Diameter: Approximately 25.8 mm to 28.5 mm (depending on casing and rings)
- Family: Part of the A. Schild 1187/1194 group (sharing architecture with calibers like 1158 and 1190)
- Function: Sweep second design, highly modular with interchangeable wheels and bridges [ 1 , 2, 3 ]
**Repair and Restoration Notes **
- Common Issue: On Watch Repair Talk, experts note a consensus that the balance wheel may bind or lose free play if an incorrect replacement balance staff or mismatched shock-resistor system is installed.
- Servicing: Because these are vintage mid-century movements, they are popular for restoration practice, though dried lubricants often require a full ultrasonic cleaning and teardown. [ 3 ]
If you are working on an AS 1187/94, let me know:Are you trying to fix a specific issue (like a stuck balance or broken mainspring)?Do you need help finding replacement parts?
AI responses may include mistakes.
[1] https://www.emmywatch.com/db/movement/a_schild–1187/
[2] https://calibercorner.com/a-schild-caliber-as-1194/
[3] https://omegaforums.net/threads/movement-id-as-1187-or-1194-in-vintage-1940s-watch.189595/
[4] https://www.watchmaterial.com/as-a-schild-1187-main-spring-replacement/
[5] https://www.watchrepairtalk.com/topic/19050-movement-as-118794/
I ordered a mainspring. I have not made very good notes on this one.
I have no idea why or how I settled on that spring I ordered.
I ordered a 711k spring?
Key spec numbers if you’re servicing it: stem W1131, balance staff U2438, mainspring 1.60 × 9.0 × 0.10 × 290mm (one source lists 1.60 × 8.0 × 0.10 × 260mm). Lift angle is listed as 52° but that figure is flagged as needing confirmation, so treat timing-machine amplitude readings with a grain of salt until you verify it. RanfftCaliber Corner
On the spring: 711K is a Bestfit/material-house number, not a GR number. It cross-references as MS-711K, 1.60 × 0.10 × 300, 9mm barrel, equivalent to GR 4486. Meanwhile Générale Ressorts’ own spec for the AS 1194 is GR4502 at 1.60 × 0.105 × 280 × 8.5. So your 711K is a hair thinner and 20mm longer than GR’s recommendation — a reasonable substitute, but not identical.











































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