What Is Seiko 4R36 Movement? Full Specs Guide 2026

Quick Answer:

The Seiko 4R36 is a 24-jewel automatic movement featuring hacking seconds, hand-winding capability, and day-date display. Core specifications include a 21,600 vph beat rate, 41-hour power reserve, and +45/-35 seconds/day factory accuracy rating. This caliber powers the majority of Seiko 5 Sports watches and select entry-level Prospex models. The 4R36 is functionally identical to the NH36—same internal components manufactured in the same facility, with different branding for Seiko-branded watches versus aftermarket sales.

This guide explains the 4R36's complete specifications, how its key features work in practice, real-world accuracy expectations, and how it compares to related Seiko calibers.

Understanding the Seiko 4R36

The Caliber 4R36 represents Seiko's most important automatic movement for everyday watches. Manufactured by Seiko Instruments Inc. (SII) in Japan, this movement powers the watches that most people encounter when they first discover mechanical timekeeping—the colorful Seiko 5 Sports lineup, entry-level Prospex divers, and countless watches from microbrands building on Seiko's proven foundation.

Introduced in 2011, the 4R36 succeeded the legendary 7S26 that had defined affordable automatic watches for decades. While the 7S26 established Seiko's reputation for bulletproof reliability, it lacked features that enthusiasts and modern buyers expected: the ability to stop the seconds hand for precise time-setting, and manual winding capability for those times when wrist motion alone wasn't enough. The 4R36 addressed both limitations while maintaining the durability that made its predecessor a legend.

The Movement's Position in Seiko's Hierarchy

Understanding where the 4R36 fits in Seiko movements lineup helps contextualize what you're getting. Below the 4R36 sits the discontinued 7S26 and its variants—simpler, cheaper, but lacking modern conveniences. Above it, the 6R35 offers better accuracy specifications and dramatically longer power reserve, but doubles the typical watch price. The 4R36 occupies the sweet spot where practical features meet accessible pricing, which explains why it appears in more Seiko watches than any other current caliber.

This market positioning—typically powering watches priced between $150-$400—means the 4R36 needs to balance capabilities against cost constraints. It does this remarkably well, delivering the features most buyers actually use while keeping prices low enough for impulse purchases and first mechanical watches.

Complete Technical Specifications

The 4R36's specifications reflect its workhorse positioning. Twenty-four synthetic ruby jewels reduce friction at critical pivot points, enabling smooth operation and extended service life. The movement beats at 21,600 vibrations per hour—six beats per second—creating the characteristic mechanical watch sweep that distinguishes automatics from quartz pieces.

Power reserve reaches approximately 41 hours when fully wound. In practical terms, this means the watch runs for about a day and a half without being worn or wound. Take off your watch Friday evening, and it might still run when you check Sunday morning—or it might have stopped. For weekend desk-workers, this becomes a consideration addressed by the manual winding feature.

Key Features in Practice

Hacking Seconds: Precision Time-Setting

The hacking feature allows precise synchronization with reference time sources—something the 7S26 predecessor couldn't do. When you pull the crown to the time-setting position (fully extended), the second hand stops completely. This enables a time-setting ritual familiar to watch enthusiasts: pull the crown when the reference source shows exactly 12:00:00, wait for your target time, then push the crown to restart the seconds hand in perfect sync.

For everyday use, hacking matters less than it might seem. Most people set their watches approximately and don't worry about second-level accuracy. But for those who care about precision—syncing with atomic clocks, coordinating with others, or simply appreciating mechanical watchmaking—hacking transforms the experience. The 7S26's inability to stop the seconds meant you were always approximating; the 4R36 enables exactitude.

Hand-Winding: Control Over Power

Unlike purely automatic movements that only wind from wrist motion, the 4R36 accepts manual winding through the crown. With the crown pushed in (normal wearing position), clockwise rotations wind the mainspring directly. Approximately 30-40 rotations brings the movement to full wind, and you'll feel increasing resistance as the mainspring approaches capacity. Stop when resistance increases noticeably—forcing beyond this point risks damage.

This feature addresses a practical limitation of 41-hour power reserves. Desk workers who remove their watches at computers, people who rotate between multiple watches, or anyone who doesn't wear a watch every day can wind their 4R36 manually rather than shaking it to start the rotor. The convenience seems minor until you've owned both types of automatic movements—the frustration of a dead watch that requires vigorous shaking to revive teaches appreciation for hand-winding capability.

Day-Date Display: Practical Complications

The 4R36 displays both day-of-week and date through windows at the 3 o'clock position. Day wheels typically offer English plus one additional language—Japanese in domestic models, Spanish or French in export versions—cycling between language options as you advance through the days. The quick-set feature allows rapid day and date adjustment through the crown's first click position without cycling through hours.

Day-date complications add practical utility that date-only alternatives lack. Knowing the day-of-week proves genuinely useful for those whose schedules don't follow strict weekday patterns. The trade-off is additional dial clutter and a slightly busier aesthetic compared to date-only or no-date alternatives.

Magic Lever Winding System

Seiko's proprietary Magic Lever winding mechanism distinguishes their automatic movements from many competitors. Traditional automatic winding only captures energy from rotor rotation in one direction—spin the other way and nothing happens. The Magic Lever converts rotor motion in both directions into mainspring winding, meaning any wrist movement contributes to power reserve regardless of the direction it causes the rotor to spin.

In practice, this bidirectional winding means the 4R36 maintains power reserve more efficiently from everyday activity. Even relatively sedentary wearers typically generate enough motion to keep their watches running. The system has proven itself across decades and millions of movements—reliable, efficient, and maintenance-friendly.

4R36 vs NH36: Understanding the Naming

The most common question about the 4R36 concerns its relationship to the NH36—are they different movements, and if so, how? The answer is simpler than the question suggests: they are identical movements with different names.

Seiko Instruments manufactures these movements on the same production lines using the same components to the same specifications. When movements go into Seiko-branded watches, they receive "4R" caliber designations and appear on spec sheets as 4R36, 4R35 (date-only variant), or similar. When the same movements sell to third-party watch manufacturers or the aftermarket for custom builds and modifications, they receive "NH" designations—NH36, NH35, and so on.

The distinction is purely commercial. Seiko maintains separate product lines for their own branded watches versus OEM and aftermarket sales. If you're buying a Seiko 5 Sports, you get a 4R36. If you're building a custom mod or your microbrand sources movements from SII, you get an Seiko NH36 movement. Inside, they're the same movement with the same reliability, same specifications, and same performance characteristics.

Comparing Seiko Movement Calibers

The 4R36 exists within a family of related Seiko movements, each targeting different market positions. Understanding these relationships helps contextualize what the 4R36 offers and when alternatives might serve better.

The 7S26: The Predecessor

The 7S26 defined affordable automatic watches for a generation. This 21-jewel movement powered the original Seiko 5 lineup and taught millions of buyers what mechanical watches could deliver at accessible prices. Its legendary reliability—some examples running continuously for 30+ years—established the reputation that makes Seiko movements trusted today.

But the 7S26 lacked features modern buyers expect. No hacking meant imprecise time-setting. No hand-winding meant shaking stopped watches back to life. These limitations felt acceptable in the 1990s but became frustrating as competitors added these features at similar price points. The 4R36 addressed both gaps while maintaining the 7S26's reliability DNA.

The 6R35: The Premium Option

Above the 4R36 sits the 6R35, Seiko's mid-range premium movement. Two key improvements justify its higher price: accuracy specifications tighten to +25/-15 seconds per day (versus the 4R36's +45/-35), and power reserve extends to 70 hours—nearly three days versus the 4R36's day and a half.

The 70-hour power reserve proves genuinely useful for weekend warriors. Remove your watch Friday evening and it still runs Monday morning. The improved accuracy specification means more examples run within ±10 seconds per day out of the box. Finishing quality improves as well—visible through exhibition casebacks, the 6R35 looks more refined than the utilitarian 4R36.

These upgrades roughly double typical watch prices. Seiko 5 Sports models with 4R36 movements retail around $250-$350; Prospex models with 6R35 calibers start around $500-$600 and extend higher. Whether the premium justifies the cost depends on how much you value the specific improvements—many buyers find the 4R36 entirely adequate.

Real-World Accuracy Expectations

The 4R36's factory accuracy specification of +45/-35 seconds per day sounds alarming if you're accustomed to quartz watches losing only seconds per month. Understanding what these numbers mean in practice—and how typical examples actually perform—prevents unnecessary disappointment.

Factory Specifications vs Typical Performance

Seiko's published accuracy range is intentionally conservative—a worst-case boundary that allows for manufacturing variation, extreme usage conditions, and the inevitable effects of time on mechanical systems. The specification ensures virtually every 4R36 leaving the factory falls within acceptable range, even if worn upside-down in temperature extremes while magnetized.

Typical out-of-box performance runs significantly better. Most 4R36 examples achieve ±10-20 seconds per day in normal wearing conditions. Well-regulated examples hit ±5-10 seconds per day. With professional regulation by a skilled watchmaker, ±3-7 seconds per day is achievable and not unusual. Your specific example may run faster or slower than average, but dramatic deviation from these typical ranges suggests something wrong rather than normal variation.

Understanding What Affects Accuracy

Mechanical watch accuracy depends on factors that quartz movements ignore entirely. The position in which you store your watch overnight—dial up, dial down, crown up—affects rate because gravity influences the balance wheel differently in each orientation. Some owners optimize storage position to compensate for their movement's natural tendencies.

Temperature swings affect the balance spring's elasticity, which in turn affects timekeeping. Extreme cold or heat during outdoor activities might cause temporary rate changes that normalize when the watch returns to room temperature. Magnetic fields from phones, laptops, and speakers can magnetize the balance spring, causing dramatic rate increases until the watch is demagnetized.

Power reserve level matters too—the force from a fully wound mainspring differs from a nearly depleted one, and this affects rate. Watches worn all day maintain more consistent power levels than those sitting on nightstands depleting gradually. Sharp impacts can shock the balance wheel out of regulation, though the 4R36's Diashock protection system minimizes this risk during normal wear.

When to Seek Regulation

If your 4R36 runs within ±15 seconds per day, professional regulation is optional—the movement performs within normal expectations. Beyond that range, or if accuracy has degraded noticeably from previous performance, a watchmaker can adjust the regulator lever for approximately $30-50. The 4R36 responds well to regulation; competent watchmakers routinely achieve ±5 seconds per day with these movements.

Watches Powered by the 4R36

The 4R36 appears across Seiko's most popular automatic watch lines, making it one of the most-produced mechanical movements in current manufacturing. Understanding where you'll encounter this caliber helps contextualize its importance to Seiko's product lineup.

Seiko 5 Sports: The Primary Home

Nearly every current Seiko 5 Sports model uses the 4R36 caliber. The SRPD series introduced the current design language—42mm cases with day-date displays, available in countless color combinations from conservative black to vivid orange. The SRPE series continued the pattern with additional colorways. Field watch styles in the SRPG series bring military-inspired aesthetics to the same 4R36 foundation.

This ubiquity makes the Seiko 5 Sports the most accessible entry point to 4R36 ownership. Pricing typically ranges from $200-$350 depending on specific model and market conditions. The diversity of available styles—from dive-inspired to field watch to dressy—means nearly everyone can find a Seiko 5 Sports that appeals to their aesthetic preferences.

Entry Seiko Prospex

Some entry-level Prospex divers share the 4R36 caliber with their Seiko 5 Sports cousins. Certain "Save the Ocean" special editions, select Samurai reissues, and specific Monster variants use this movement rather than the more expensive 6R alternatives. These watches offer true diver specifications—200m water resistance, ISO certification—at prices closer to fashion watches than professional tool watches.

The presence of 4R36 in Prospex models demonstrates Seiko's confidence in the caliber's durability. Dive watches face pressures, temperature changes, and demanding conditions that expose movement weaknesses quickly. That Seiko trusts the 4R36 in this application speaks to its robustness.

Seiko Presage Select Models

Budget-oriented Presage cocktail time variants occasionally feature the 4R36 or its date-only sibling, the 4R35. These dress watches prioritize dial finishing and case refinement over movement premium—choosing the proven workhorse caliber allows more budget allocation to visible components. The result is impressive dial work at accessible prices, powered by the same reliable caliber running in Seiko 5 Sports divers.

Operating the 4R36: Crown Positions

The 4R36 uses a standard three-position crown system that becomes intuitive quickly. Understanding each position prevents frustration during time-setting and date adjustment.

Position zero—crown pushed fully in—represents normal wearing state. In this position, rotating the crown clockwise winds the mainspring manually. You'll feel the winding action as slight resistance, increasing as the spring approaches full tension. Stop when resistance increases notably; forcing beyond risks mainspring damage.

The first click out accesses day and date quick-set. Rotating counter-clockwise advances the day display; rotating clockwise advances the date. This allows rapid adjustment without cycling through hours. Important: avoid using quick-set between approximately 9 PM and 3 AM, when the date-change mechanism is engaged. Forcing adjustment during this window can damage the date-change gearing.

Fully extended position enables time-setting with hacking engaged. Pulling the crown to this position stops the seconds hand completely, allowing precise synchronization. Rotate to set time, then push the crown back to position zero to restart the movement.

Maintenance and Service Expectations

The 4R36 inherits the legendary durability that made its 7S26 predecessor a watch-world legend. With normal wear and basic care—avoiding unnecessary shocks, keeping the crown properly seated, occasional cleaning—expect 10-15 years of reliable operation before service becomes necessary. Many examples exceed this dramatically; the movement's fundamentally sound engineering rewards owners who treat it reasonably.

Recognizing Service Needs

Mechanical watches don't fail suddenly like dead batteries in quartz pieces. Instead, they signal declining health through gradual changes that attentive owners notice. Accuracy degrading beyond normal expectations—particularly if previously the watch ran well—suggests lubricant breakdown or accumulated wear affecting regulation. Noticeably reduced power reserve, where a fully wound watch runs shorter than before, indicates mainspring fatigue or escapement issues.

Physical symptoms matter too. A rotor that sounds gritty or rough during rotation, hand-winding that feels scratchy rather than smooth, or a crown that's become difficult to operate all suggest internal issues requiring attention. None of these mean imminent failure, but addressing them promptly prevents minor problems from becoming major repairs.

Service Options and Costs

Basic service—disassembly, cleaning, lubrication, and regulation—typically costs $100-150 from competent watchmakers. This restores the movement to like-new operating condition without replacing components. Full overhauls that include parts replacement as needed run $150-250, appropriate for movements with significant wear or damage.

The 4R36's accessibility creates an interesting economic reality: movement replacement often costs less than comprehensive service. New NH36 movements retail around $60-100 from reputable suppliers. A watchmaker charging $50-75 for installation makes complete movement replacement competitive with overhaul pricing. This option maintains fresh factory specifications without the uncertainty of whether aged components will last another service interval.

Seiko recommends service every 3-5 years, but this conservative guidance assumes warranty protection concerns and ideal maintenance practices. Many 4R36 movements run 10+ years without service, accumulating running hours that would terrify Seiko's service department. The movement's forgiving nature—its tolerance for delayed maintenance, its graceful degradation rather than sudden failure—makes it genuinely low-maintenance for typical owners.

The 4R36's Strengths

Proven Reliability

The 4R36 descends from decades of Seiko automatic movement development, incorporating lessons learned from millions of watches across multiple generations. The 7S26 foundation proved itself in environments ranging from office desks to construction sites, from tropical humidity to arctic cold. The 4R36 builds on that legacy with refined manufacturing and updated features, maintaining the fundamental robustness that made Seiko automatics legendary for surviving conditions that destroy lesser movements.

Modern Features at Accessible Prices

Hacking seconds and hand-winding capability sound basic to experienced collectors, but these features remain premium in many market segments. Competing Swiss movements with equivalent functionality start at significantly higher prices—often $500+ for the complete watch. The 4R36 delivers these conveniences in watches costing $200-$350, democratizing features that once distinguished expensive timepieces from budget alternatives.

Exceptional Serviceability

Any competent watchmaker anywhere in the world can service a 4R36. The movement's popularity ensures widespread familiarity, abundant parts availability, and established procedures that minimize service time and cost. This accessibility matters for long-term ownership—a movement nobody can service is worthless regardless of its original quality. The 4R36 will find skilled hands whenever service becomes necessary, practically anywhere you might live or travel.

Massive Aftermarket Ecosystem

The NH36 designation opens access to one of watchmaking's largest aftermarket ecosystems. Thousands of compatible cases, dials, hands, bezels, and bracelets exist for 4R36/NH36-based builds. This compatibility enables customization ranging from simple dial swaps to complete custom builds—all powered by the same proven caliber. Few movements offer comparable aftermarket support at any price point.

The 4R36's Limitations

Accuracy Compared to Premium Alternatives

The factory specification of +45/-35 seconds per day places the 4R36 firmly in standard mechanical territory rather than chronometer territory. Swiss COSC certification requires +6/-4 seconds per day—an order of magnitude tighter. While typical 4R36 examples significantly outperform their factory specification, buyers who compare against atomic references daily may find the variation frustrating. For most wearers, however, the practical accuracy proves entirely adequate for daily use.

41-Hour Power Reserve

Just under two days of power reserve means weekend breaks from wearing require Monday morning restarts. Those who rotate between multiple watches or simply prefer not to wear watches on weekends will find their 4R36 stopped when they return. The hand-winding capability mitigates this—a quick wind starts the movement without shaking—but the limitation remains compared to premium movements offering 70-80 hours that bridge weekends effortlessly.

Utilitarian Finishing

Through exhibition casebacks, the 4R36 reveals its workhorse nature rather than artisan finishing. No Geneva stripes adorn the mainplate. No polished bevels catch the light. The movement works beautifully but looks industrial—functional rather than decorative. Buyers who appreciate movement aesthetics through display backs may prefer watches with more elaborately finished calibers, though these typically cost significantly more.

Six-Beat Sweep

The 21,600 vph frequency produces six beats per second—visible as the characteristic mechanical sweep across the dial. Higher-frequency movements at 28,800 vph (eight beats per second) create smoother sweeps that some enthusiasts prefer. The difference is subtle and arguably irrelevant to practical timekeeping, but those who notice find the six-beat motion slightly "jumpier" than eight-beat alternatives.

Frequently Asked Questions

Is the Seiko 4R36 a good movement?

The 4R36 represents excellent value for watches in its price range. Proven reliability inherited from the legendary 7S26, modern conveniences including hacking and hand-winding, and day-date complications combine at prices typically between $200-$400. For this segment, the 4R36 stands among the best movement choices available from any manufacturer. Its limitations—moderate accuracy specifications, 41-hour power reserve, utilitarian finishing—matter less than its strengths for most typical buyers.

How accurate is the Seiko 4R36?

Factory specifications allow +45/-35 seconds per day, but this conservative rating understates typical performance. Most examples run ±10-20 seconds per day under normal conditions. Well-regulated examples achieve ±5-10 seconds per day. Professional regulation can tighten this further to ±3-7 seconds per day. For practical daily wear, the 4R36 provides accuracy adequate for any normal use case.

Is 4R36 the same as NH36?

Yes—identical movements with different marketing names. Seiko Instruments manufactures both on the same production lines using identical components. The "4R36" designation appears in Seiko-branded watches; the "NH36" designation applies to movements sold to third-party manufacturers and the aftermarket for custom builds. Performance, reliability, and specifications are the same regardless of which label appears on your movement.

How long does the 4R36 last?

Expect 10-15 years of reliable operation before service becomes necessary with normal use and basic care. Many examples significantly exceed this, running 20+ years before requiring attention. The movement descends from the 7S26, whose legendary longevity proved itself across decades and millions of watches. Barring abuse or unusual circumstances, a 4R36 purchased today should still run when you're ready to pass it to the next generation.

Can I manually wind a 4R36 watch?

Yes—this is one of the key improvements over the 7S26 predecessor. With the crown pushed in (position 0), rotate clockwise to wind the mainspring. Approximately 30-40 rotations brings the movement to full wind. You'll feel increasing resistance as the mainspring approaches capacity; stop when resistance increases noticeably to avoid damage. This feature proves particularly useful for desk workers, watch rotators, and anyone who doesn't wear their watch daily.

What is the power reserve of the 4R36?

Approximately 41 hours when fully wound—roughly a day and a half of running time without wearing or winding. This bridges overnight storage comfortably but typically doesn't survive complete weekends. If you remove your watch Friday evening, expect to restart it Sunday or Monday. The hand-winding capability makes this less frustrating than it might seem; a quick wind starts the movement without the vigorous shaking that purely automatic movements require.

Conclusion

The Seiko 4R36 exemplifies what volume manufacturing and decades of refinement can achieve: a reliable, feature-complete automatic movement at prices that make mechanical watchmaking accessible to virtually everyone. It won't impress with exotic finishing or chronometer-grade accuracy, but it will run reliably for years, accept service from any competent watchmaker anywhere in the world, and provide the tangible mechanical experience that makes automatic watches engaging in ways that quartz alternatives cannot match.

For Seiko 5 Sports buyers, the 4R36 ensures years of trouble-free daily wear. For modders using the NH36 equivalent, it provides a proven foundation for creative builds. For first-time mechanical watch buyers, it delivers an authentic automatic experience without the investment premium movements demand. In each role, the 4R36 delivers exactly what its position promises—not perfection, but excellent value and proven reliability.

Those needing better accuracy, longer power reserve, or finer finishing should consider the 6R35 or higher—and should budget accordingly. For everyone else, the 4R36 offers the sweet spot where practical features meet accessible pricing, which is exactly why it powers more current Seiko watches than any other caliber.