Helvetia 51L

Manual · 16‴ · Switzerland · 1930

Dimensions
36.5 mm
Height
4.20mm
Jewels
15
Power reserve
32h
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 16‴
Shape Round
Complications Sub Second , Chronograph Second
Hand count 3
Hand sizes 1.50 x 0.90 / 0.22mm
Further measures
Mounting Diameter (Dm): 35.75mm
Stem height (T): 1.9mm
Mounting Height (F): 0.5mm
Origin & References
Manufacturer Helvetia
Country Switzerland
Launch year 1930
COSC certified No
Signature
ca. 1930: 8
Notes
Remarks: open face calibre
Other data: balance staff: U2668 stem: W1774 mainspring / battery: Zf1416, 1.70 x 13.0 x 0.18 x 330mm
Family

Series 51L - suffix I

51L: open face calibre
51S: hunter calibre
suffix I: meaning unknown
Related calibers
Helvetia 51L Helvetia 51LI Helvetia 51S Helvetia 51SI