Movement · Seiko · automatic
Seiko 7S26 movement
Seiko 7S26 is an automatic movement by Seiko: 27.4 mm1seller listing across, 4.9 mm1seller listing high, 213 jewels, beating at 21,600 bph3, 41 h3 of power reserve. Fitting figures: hand holes hour 1.5 · minute 0.9 · second 0.21 mm; date window 3H (full table). 5 watches in our base use it (list).
What can replace the 7S26
11 calibres of the Seiko NH / 4R / 7S group checked against the 7S26: diameter, height, hand holes, date window, crown and dial feet. A verdict marked “not confirmed” lacks one of those figures for the 7S26 or the other calibre.
Not published, so not checked in several comparisons:
- hand holes for 4R36, 7S36, 4R34, 4R35, NH38 and NH39
- crown position for 7S26, 4R36, 7S36, 4R34, 4R35, NH38 and NH39
- dial feet for 7S26, 4R36, 7S36, 4R34, 4R35, NH38 and NH39
7S26 → 4R36
Fits with changes· not confirmed- =diameterSame movement diameter: 27.4 mm.
- ≠height4R36 is 0.42 mm taller (5.32 mm vs 4.9 mm): check the room under the crystal and the case back; the hands sit higher.
- =dateDate window at 3H on both.
7S26 → 7S36
Fits with changes· not confirmed- =diameter7S36’s movement diameter matches 7S26’s casing diameter: 27 mm.
- ≠height7S36 is 0.1 mm thinner (4.8 mm vs 4.9 mm): the dial and hands sit lower, so a spacer or a different stem height may be needed.
Not published, so not checked: date position for 7S36.
7S26 → 4R34
Fits with changes· not confirmed- =diameterSame movement diameter: 27.4 mm.
- ≠functions4R34 adds a 24-hour hand: it needs a dial and hand set made for it.
- ≠date4R34 has no day wheel: a day-date dial would show an empty day window.
- =dateDate window at 3H on both.
Not published, so not checked: height for 4R34.
7S26 → 4R35
Fits with changes· not confirmed- =diameterSame movement diameter: 27.4 mm.
- ≠height4R35 is 0.42 mm taller (5.32 mm vs 4.9 mm): check the room under the crystal and the case back; the hands sit higher.
- ≠date4R35 has no day wheel: a day-date dial would show an empty day window.
- =dateDate window at 3H on both.
7S26 → NH36
Fits with changes· not confirmed- =diameterSame movement diameter: 27.4 mm.
- ≠heightNH36 is 0.42 mm taller (5.32 mm vs 4.9 mm): check the room under the crystal and the case back; the hands sit higher.
- ≠handsDifferent hand holes (minute 0.9 vs 0.88 mm): new hands.
- =dateDate window at 3H on both.
7S26 → NH35
Fits with changes· not confirmed- =diameterSame movement diameter: 27.4 mm.
- ≠heightNH35 is 0.42 mm taller (5.32 mm vs 4.9 mm): check the room under the crystal and the case back; the hands sit higher.
- ≠handsDifferent hand holes (minute 0.9 vs 0.88 mm): new hands.
- ≠dateNH35 has no day wheel: a day-date dial would show an empty day window.
- =dateDate window at 3H on both.
7S26 → NH38
Fits with changes· not confirmed- =diameterSame movement diameter: 27.4 mm.
- ≠heightNH38 is 0.42 mm taller (5.32 mm vs 4.9 mm): check the room under the crystal and the case back; the hands sit higher.
- ≠dateNH38 has no day wheel: a day-date dial would show an empty day window.
- ≠dateNH38 has no date: a dial with a date window would show nothing in it.
7S26 → NH39
Fits with changes· not confirmed- =diameterSame movement diameter: 27.4 mm.
- ≠heightNH39 is 0.42 mm taller (5.32 mm vs 4.9 mm): check the room under the crystal and the case back; the hands sit higher.
- ≠dateNH39 has no day wheel: a day-date dial would show an empty day window.
- ≠dateNH39 has no date: a dial with a date window would show nothing in it.
3 more calibres in the group fit less well; compare any of them with the movement comparison.
All 7S26 figures
Every figure we hold for the 7S26, with its source. Where sources disagree, each value is shown.
Running
Accuracy and care
- Do not set the date
- 21:00–04:003
Fitting: dial, hands, stem
Origin
- Made from
- 19962secondary source
Not published yet
- Accuracy (maker): not in the documents we read
- Lift angle: not in the documents we read
- Hacking seconds: not published by Seiko
- Dial feet: not in the documents we read
Versions
7S26A · 7S26B
7S26 questions
What dial, hands and case fit the 7S26?
Which watches use the 7S26?
5 watches in our base name the 7S26: SKX007, SKX009, SKX013, SNK809, SNXS79.
When should you not change the date on the 7S26?
Not between 21:00 and 04:00, per Seiko: the 7S26’s date change is engaged then, so move its hands past 04:00 before using the quick-set.
Source [3]
What can replace the 7S26?
From the published figures, the closest is the 4R36: fits with changes, not confirmed for every part, with 10 more in the same group. 4R36 is 0.42 mm taller (5.32 mm vs 4.9 mm): check the room under the crystal and the case back; the hands sit higher.
More on movements
- Seiko movementsEvery Seiko calibre with its key figures
- 7S26 vs 4R36Side by side with the 4R36, drawn to the same scale
- 7S26 vs NH35Side by side with the NH35, drawn to the same scale
- Movement comparisonPut the 7S26 next to up to three other calibres
- Quartz vs automatic watchWhere the 7S26 sits: accuracy, power and upkeep, in numbers
- Watch movement types explainedAutomatic, hand-wound, quartz, solar and digital modules side by side
- Watch accuracy calculatorCheck a 7S26 against Seiko's figures
- All movementsCatalogue by maker and type
Sources
Documents checked · Report a wrong number
- 1Esslinger & Co. — Genuine Seiko 3 Hand Automatic Watch Movement 7S26 (product page, movement marked 7S26C) · html · read
- 2Grail Watch — Grail Watch Reference: Seiko Cal. 7S26 · html · read
- 3Seiko Watch Corporation — Instructions: Seiko Automatic Diver's Watch Cal. 4R15/4R16/4R35/4R36/7S26/7S35/7S36 (English) · pdf · read
- 4Worn & Wound — Seiko SKX007 Review - Worn & Wound · html · read
- 5WatchBase — Seiko SKX009K2 : Seiko SKX009 Black / Stainless Steel (WatchBase) · html · read
- 6Watchoutz — Seiko 5 Sports Automatic 200M Diver Black-Dial SKX013K1 (product page) · html · read
- 7The Modest Man — Seiko SNK809 review · html · read
- 8Vivir — Seiko 5 SNXS79 Review: The Everyday Underdog Champion · html · read
- 9Grail Watch — Grail Watch Wiki: Seiko 6R15 · html · read
- 10Grail Watch Reference — Time Module Inc. brand listing (Grail Watch Reference) · html · read