ETA Caliber 2851 Watch Movement

Manufacturer	ETA
Caliber Number	2851
Base Caliber	ETA 2850
Family	ETA 2800 series “Gabarit”
Movement Type	Mechanical, manual-wind
Lignes	11.5”’
Diameter	25.6mm
Height	4.3mm
Jewel Count	Varies
Beat Rate	21,600 vph, 3 Hz
Lift Angle	52 degrees
Power Reserve	~38 hours
Hand-Windable?	Yes
Anti-Shock Device	Incabloc
Hand Count	3
Hand Sizes	1.5mm / .90mm / .25mm
Functions	Central hours; central minutes; central sweeping seconds
Hacking Seconds?	Yes
Country of Manufacture	Switzerland, Swiss made
Known Models	(Add your watch to the comments below…)

The ETA caliber 2851 is a vintage time-only manual-wind mechanical movement. It is a true no-date movement.

This caliber is an early member of the ETA 28XX family of movements (Gabarit).

Documentation for this caliber was found as far back as 1976.

2851 VS 2850:

The ETA calibre 2851 is basically a lower beat rate version of the cal. 2850. The 2850 beats at 28,800 vph (4 Hz) and the 2851 has a frequency of 21,600 vph (3Hz).

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