Vostok Caliber 2431

Manufacturer	Vostok (Boctok)
Caliber Number	2431
Movement Type	Automatic, self-winding mechanical
Diameter	24mm
Height	6.3mm
Jewel Count	32 jewels (see below…)
Beat Rate / Frequency	19,800 bph / 2.75 Hz
Lift Angle	Unconfirmed
Accuracy Rating	-20/+60 seconds/day
Power Reserve	Up to 31 hours
Hand-Windable?	Yes
Anti-Shock Device	Vostok 3 prong
Hand Count	3
Functions	Central hours; central minutes; central sweeping seconds; date at 3:00 or 6:00
Hacking Seconds?	No
Country of Manufacture	Made in Russia
Known Models	Sturmanskie Arktika Heritage 24 Hours, Sturmanskie Open Space Heritage (Add your watch to the comments below…)

The Vostok caliber 2431 is a 24 hour dial movement – instead of the hands going around the dial twice per day (12 hours), the hour hand makes a full rotation only once.

Jewel Count:

There are some inconsistencies with the number of jewels in the 2431. The most common jewel count is 32 jewels. However, there are some quotes of 31 jewels, as well as 2431 powered watches with “17 Jewels” on the dial.

2431A VS 2431B:

There is a 2431B, but the differences are unconfirmed. Does it have 31 jewels and the 2431 has 32 jewels? If you know anything about this, please add to the comments below so that this section can be updated..

With other variants such as 2431/1, 2431/2, etc., it appears to be related to the style of datewheel (date at 3, date at 6, different colors).

Loose Crown?

If you have a 2431 powered watch (Vostok Komandirskie, for example) and the crown is jiggly or wobbly when unscrewed, it is supposedly a design feature that protects the crown and stem from being broken if the watch is dropped or bumped against something with the crown unscrewed.

Additional Resources:

• Official user manual from Sturmanskie (pdf)