Seiko 7S26 Movement Details

Seiko caliber 7S26 is an automatic watch movement. Production started around 1996.
Find watches with this movement on eBay.

Sub-brands:	Seiko 5, S-Wave, Recraft
Power reserve:	41 hours
Accuracy:	+45/-35 seconds/day
Day / date?	Day + date
GMT / world time?	No
Chronograph?	No
Hacking?	No
Rate:	21,600 bph
Number of jewels:	21
Lift angle:	53º
Size / diameter:	27.0mm
Height:	4.9mm
Notes:	The same as cal. 7S25 but with day display (as well as date). The difference between 7S26A and 7S26B is an upgrade to an Echtacron-style regulator for easier adjustment. Changes in 7S26C are the addition of a lower arbor jewel and making all four date dial guard screws identical – no more frustratingly small cross-head screw! The difference between the 7S26 and cal. 7S36 is the addition of a lower bridge for third wheel and pinion in the 7S36, which gives it two extra jewels. The increased jewel count might imply better performance and accuracy but in reality there's probably little or no difference. Note that the date wheel used for 7S26A and 7S26B is not compatible with 7S26C.
PDF guides:	Instruction manual (English) Instruction manual (English & Japanese) Instruction manual for diver's watch (English) Technical guide : 7S26A & 7S36A Technical guide : 7S26B & 7S36B Technical guide : 7S26C & 7S36C
Related movements:	7S25 7S35 7S36 7S55

Part Codes

Stem code:	351260 (tap 10), 351261 (tap 10)
Balance wheel code:	310020, 310197
Mainspring code:	201024, 201075, 201083
Date wheel code:	878206 (black on white), 878207 (white on black), 878280 (black on white), 878281 (white on black), 878282 (black on gold)
Screw codes:	012123 (stud screw), 012168, 012354, 012420, 012539 (second reduction wheel screw), 012919 (ratchet wheel screw), 016705