Seiko Caliber 6N22

Manufacturer	Seiko Time Corp.
Caliber Number	6N22, 6N22A
Movement Type	Quartz, battery-powered
Diameter	18.5mm (16.1mm x 18.2mm)
Casing Diameter	18.1mm
Height	2.79mm
Jewel Count	No jewels (0)
Frequency	32,768 Hz
Battery Cell	SR621SW / 364 (silver oxide, 1.55 V)
Battery Life	~3 years (36 months)
Stem	0351-332
Coil Part #	4004274
Hand Count	3 hands
Functions	Central hours; central minutes; central seconds; date at 3:00 or 6:00
Hacking Seconds?	Yes
Country of Manufacture	Made in Japan
Known Models	(Add yours in the comments below…)

The Seiko caliber 6N22 (6N22A) is a 3-hander analog quartz movement. It is made in Japan and has no jewels. Timepieces with this movement feature a calendar date at 6:00.

This appears to be the Seiko-only version of the SII/TMI calibre VJ22 (VJ22A).

Accuracy Rating:

According to official Seiko documentation, they claim that the average monthly rate of the 6N22 is less than +/- 20 seconds per month under normal conditions (source).

With regards to the 6N22, “normal” temperatures should be within the range of 5°C ~ 35°C (41°F ~ 95°F) for the best accuracy, however, the movement can still operate between -10C ~ 60C (14F ~ 140F).

Changing the Battery:

The battery cell number in the calibre 6N22 is SR621SW / 364.

Datewheel Options:

The 6N22 has various datewheel options depending on color and position of the calendar window on the dial:

• Black text on white background at 3:00 (0878 152, 878152)
• White text on black background at 3:00 (0878 155, 878155)
• Black text on white background at 6:00 (0878 160, 878160)
• White text on black background at 6:00 (0878 161, 878161)

6N22 VS 6N42:

The cal. 6N42 (which was replaced by the 6N52) is essentially a larger diameter version of the 6N22.

	6N22	6N42
Outside Diameter	18.5mm	26.4mm
Casing Diameter	18.1mm	25.6mm
Height	2.79mm	2.79mm

6N22 VS 6N23:

There is a similar caliber 6N23 with the main difference being that the 6N22 has a date and the 6N23 has a day of the week and date.

Additional Resources:

• Official Seiko instruction manual (pdf)