These 5 Seiko Movements Made the Brand King of Value, Reliability and Innovation

Seiko is one of the most beloved watch brands in the world because it offers unrivaled value at every price level, across a vast catalog of designs that covers every imaginable taste and need.

When fans are initially drawn to the Japanese king of watchmaking, it is often through the combination of looks and affordability. But anyone who digs a little deeper — and it is hard not to get hooked and sucked in — quickly learns that the secret to Seiko’s success is its movements.

Photo by Zen Love for Gear Patrol

From the beginning, Seiko has done everything in-house, making it one of the few vertically integrated watchmakers in the game. The lack of middlemen allows the brand to continuously push innovation while keeping prices low.

Countless watch enthusiasts began their journey into the world of automatic movements with a Seiko, exemplified by the legendary SKX dive watch, dubbed “the watch that launched a million collections.”

Grand Seiko

Seiko’s research and development department has pushed the boundaries of what mechanical movements can do, from releasing one of the first mechanical chronographs in 1969 to making automatic GMTs accessible to everyone in 2022.

Above all, Seiko is known for reliability, like with the affordable workhorse movements that dominated the 1990s to the present day, and accuracy, like with the Grand Seiko Spring Drive, which many watch experts call the best mechanical watch movement ever made.

Here are five of the most important Seiko watch movements every fan should know about, along with several honorable mentions.

4R35/36: The Ultimate Workhorse

Zen Love

• In Use: 2011 – Present
• Power Reserve: 41 hours
• Frequency: 21,600
• Jewels: 24

Seiko introduced the 4R family in 2011 as its new workhorse automatic movement. It powers most of the 5 Sports and lower-end Presage watches, along with some Prospex models.

The 4R family comprises Seiko’s entry-level automatic movements, predominantly found in watches under $500, offering unrivaled reliability and accuracy for that price range.

7S26: Time Tested Reliability

Photo by Brad Lanphear for Gear Patrol

• In Use: 1996 – 2020
• Power Reserve: 40 hours
• Frequency: 21,600
• Jewels: 21

No affordable automatic movement has earned a stronger reputation for long-term reliability than the 7S family. The vintage Seiko market is flush with SKX and Seiko 5 watches from the late 1990s and early 2000s that still keep good time thanks to this unflappable workhourse.

The 7S family was phased out in favor of the 4R family in the 2010s, but the two movements are virtually interchangeable. If an old 7S movement finally kicks the bucket, a watchmaker can plug in a new 4R or NH movement (more on that below) and the vintage Seiko will work like new.

4R34: Leveling the Playing Field

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• In Use: 2022 – Present
• Power Reserve: 41 hours
• Frequency: 21,600
• Jewels: 24

The impact that the Seiko caliber 4R34, with its caller GMT complication, had on the watch market cannot be understated. Before its release in 2022, GMT complications were almost exclusively reserved for the luxury watch market.

The 4R34, placed initially in the Seiko 5 Sports GMT, single-wristedly created a sub-$1,000 GMT market that had never existed. Three years later, it has become one of the most significant growth areas for the industry and made the GMT one of the most sought-after complications.

9R15/65 Spring Drive: Unmatched Accuracy

Seiko

• In Use: 2004 – Present
• Power Reserve: 72 hours
• Frequency: 28,800
• Jewels: 30

Technically, you could call the Grand Seiko Spring Drive an automatic-quartz hybrid, but that would be a disservice to the 9R movement family’s engineering precision. How this movement functions is notoriously difficult to explain, and I am not one of the few qualified people to do so.

Suffice it to say that the Spring Drive’s reputation speaks for itself. Most watch experts and enthusiasts, myself included, agree that the 9R family of movements is one of the greatest, if not the greatest, mechanical movements ever created.

6139 Chronograph: The Great Race

Seiko

• In Use: 1969-1978
• Power Reserve: 40 hours (est.)
• Frequency: 21,600
• Jewels: 17

In 1969, a group of Swiss watchmakers, including TAG Heuer and Zenith, collaborated to develop the first automatic chronograph. On the other side of the world, Seiko secretly created its own automatic chronograph simultaneously.

The Swiss won the race, but Seiko’s solo effort is arguably more impressive. It resulted in the caliber 6139, which powered the iconic Speedtimer.

Seiko has continued to innovate automatic chronographs ever since, and the modern evolution of the 6139 is the 8R46, found in contemporary automatic Speedtimer references.

Honorable Mentions

6R15/35/55 Auto-Manual

The 6R series is the more refined counterpart to the 4R series. These calibers are almost exclusively found in the Presage collection, with the Alpinist being the lone exception.

Seiko

The major differences compared to the 4R calibers are a higher beat frequency of 28,800, halfway to the 36,000 Hi-Beat mark, and a longer power reserve of 70-72 hours. It also allows the wearer to wind the watch manually, along with its ever-present automatic winding.

9S85/A5 Hi-Beat

Grand Seiko’s 36,000 Hi-Beat movements, which fall within the 9S caliber group, are Seiko Group’s second most prestigious movements behind the Spring Drive.

Grand Seiko

First developed in the 1960s, the high beat frequency results in a nearly fluid sweep of the second hand. They also provide an accuracy of +5/-3 seconds per day and have an 80-hour power reserve.

An argument can be made that a 9S Hi-Beat movement is better to own in the long run than a 9R Spring Drive because it is more affordable and convenient to service. Any respectable watchmaker can service a 9S, but a 9R should only be serviced by Grand Seiko.

6306/9 Dive Watches

Breaking down Seiko’s pantheon of historical movements would require a separate, much longer article. But the pre-modern movements that built the Japanese watchmaker’s reputation deserve acknowledgment, so I’ll single out the 6306/9 as the best example.

Photo by Zen Love for Gear Patrol

Seiko’s most appreciated historical movements from the 1960s, 1970s and 1980s are tied to specific watches, with the reputation of the movement growing alongside that of the watch for those to appreciate the connection.

For the 3606/9, it is the Seiko ‘Turtle’ dive watch, first released in 1976. A fun fact is that the 3606 was only released in the Japanese domestic market, and the 3609 was its counterpart for the rest of the world. The only functional difference is that the former had hacking and the latter did not.

NH Movements from Seiko Instruments Inc. (SII)

Seiko is also one of the leading producers of third-party movements that literally power the micro-brand industry. The NH family of automatic movements, found in brands like Unimatic, Vaer and Nodus, is a clone of the 4R family.

Seiko’s wholesale NH34 and meca-quartz movements have enabled startups to produce affordable GMT and chronograph watches.

Decoding the calibers

Every watch movement maker has a system for naming and organizing calibers, and Seiko’s is among the easiest to learn and understand.

Movements are grouped into families indicated by the first two digits of the caliber. Since the 1990s, it has been a number and letter combination. For example, the 4R family has many iterations, but the most common are the 4R35 and 4R36.

Photo by Brad Lanphear for Gear Patrol

Different calibers within the same family can represent subsequent generations or different complications. For example, the 4R35 displays the time and date, while the 4R36 displays the time, date and day.

Finally, some calibers end in a letter. This denotes minor variations within a caliber and goes in order, starting with A. Sometimes, it represents updates to fix an issue, and other times, it denotes variations for different markets.

Every Seiko watch dating back to the 1960s has the movement caliber printed on the case back, making it easy to spot whether you’re buying a used watch or a new one without detailed information provided by the seller.

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