Damas 18.5" hunter (Beguelin, BTC)

Manual · 18.5‴ · Switzerland · 1925

Also known as: BTC 18.5'''hunter, Beguelin 18.5'''hunter

Dimensions
42.8 mm
Height
5.45mm
Jewels
15
Power reserve
37h
Timegrapher
Beat rate
18,000bph
Frequency
2.5Hz

Reference: healthy amplitude ≈ 270–315° fully wound (>200° at 24 h); beat error ideally < 0.5 ms.

Movement
Movement type Manual
Winding type Stem Winding (Crown)
Setting type Stem Set (Crown Pull)
Escapement type Swiss Lever
Control type Balance Wheel
Regulator type Pinned Regulator (or Index Regulator)
Specifications
Lignes 18.5‴
Shape Round
Complications Sub Second
Hand count 3
Hand sizes 1.90 x 1.10 / 0.29mm
Further measures
Mounting Diameter (Dm): 41.65mm
Stem height (T): 2.8mm
Mounting Height (F): 0.8mm
Origin & References
Manufacturer Damas
Country Switzerland
Launch year 1925
COSC certified No
Signature
ca. 1925: - 10498
Notes
Remarks: hunter calibre
Option: bimetallic screw balance with 2 adjustment screws (example)
Breguet hairspring
in late samples stem mechanism without setting-lever spring (example)
Other data: balance staff: U1137 mainspring / battery: Zf3409, 1.90 x 16.0 x 0.20 x 460mm