Seiko FAQ

The SRPD65 for most wrists — 42.5 mm, 46 mm lug-to-lug, the 4R36 movement which hacks and hand-winds, and 100 m water resistance. If your wrist is under about 6.25 inches, the SRPG37 at 39.4 mm is the better fit. The full first-Seiko guide is here.

Around $250–$320 gets you a 4R36 automatic with 100 m water resistance, which is enough watch that you will not outgrow it. Below that you are into 30 m watches that cannot get wet; above about $400 you are buying a genuine ISO 6425 diver, which is a real upgrade but not a necessary first one.

For what it charges, yes and by a clear margin — Seiko manufactures its own movements including hairsprings, which very few companies at any price do. Whether it counts as “luxury” is a separate question and has its own page.

The case and the certification, not usually the movement — both lines use the 4R36 at overlapping prices. A Prospex diver is 200 m with a screw-down crown and an ISO 6425 marking; a Seiko 5 Sports is 100 m with a push-pull crown and no marking. Full comparison.

Measure across the top of your wrist, edge to edge. That figure in millimeters is roughly the longest lug-to-lug you can wear without overhang — and lug-to-lug, not case diameter, is what determines fit. Our small-wrist page ranks on it.

Usually not, down to about a 6.5-inch wrist. The cushion case turns down sharply at the lugs so its 47.7 mm lug-to-lug is shorter than plenty of 42 mm watches. This is the most common misjudgement in the whole category.

Seiko publishes it fairly consistently for the Prospex and 5 Sports lines and inconsistently elsewhere. Where it is missing, our spec tables say “Not published by Seiko” rather than estimating — an honest gap beats an invented millimeter on a page someone is using to decide whether a watch fits.

The 100 m 5 Sports references, yes. The 30 m classic Seiko 5s such as the SNK809, no — that rating covers hand-washing and rain only. What each rating permits.

That the watch was tested to ISO 6425, which adds condensation resistance after thermal shock, survival at 125% of rated pressure, legibility at 25 cm in darkness, magnetic resistance and bezel requirements on top of the pressure test. A plain 200 m watch has passed only the pressure test.

Yes. The rubber gaskets sealing the case compress and dry out over years regardless of use. A watch that actually goes in water should be pressure-tested every few years and after any service.

Architecturally yes — same manufacturer, dimensions, beat rate, reserve and construction. The difference is stated regulation and which division sells it. The comparison in full.

You have a 7S26, which was designed without either feature to reduce cost on a high-volume movement. The 4R36 that replaced it added both. 7S26 reference.

Seiko specifies the 4R family at -35 to +45 seconds per day and the 6R35 at -15 to +25. Those are production tolerances, not promises about your individual watch — a watch gaining twenty seconds a day is within specification. A watchmaker can usually regulate it much tighter.

No. The 7S26, 4R36 and 6R35 all run at 21,600 vph — six beats per second. Stepping up the Seiko range buys power reserve and a tighter tolerance, not a smoother sweep. Why that is.

No. The mainspring slips at full tension by design, so continuing to turn the crown does nothing. Twenty to thirty turns from stopped is plenty.

Between roughly 9 pm and 3 am the automatic date-change gearing is partially engaged, and forcing the quickset against it can damage the date wheel. The correct sequence.

Japanese Domestic Market. It covers both Japan-only references — SARB, SARY, SBDC, SZSB prefixes — and the J-suffix assembly marking on internationally sold references. Only the first is a genuinely different watch. Full explanation.

Not by any published specification — Seiko lists identical dimensions, movements and ratings for both. The widely repeated regulation claim is one we could not verify from any documentation. What actually differs.

It varies by country and sometimes by individual service center. Many gray-market sellers substitute their own warranty, which is often more usable. Establish which one you are getting before you buy.

It scratches far more easily — roughly 700 Vickers against 2,000 — and it chips rather than cracks under sharp impact, which on a watch whose water rating depends on the crystal is arguably the better failure mode. The full comparison.

22 mm for the SRPD/5KX family, the Turtle, the Samurai and the SSK GMTs; 20 mm for the SRPG, SPB and Presage references; 18 mm for the older SNK and SNXS Seiko 5s. Strap options by width.

No, and we say so on every page. We compile published manufacturer specifications, cite the standards behind them, pull prices live and show the arithmetic. The methodology in full.

They come from Amazon’s product data API and carry the date they were verified — currently Jul 24, 2026. Any price older than 48 hours is not displayed at all; the button falls back to “Check price” rather than showing a stale number.

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Email info@springanddial.com with the page, the reference number, the figure you believe is wrong, and where the correct one is published. Material corrections are made and dated on the page.