The Seiko 7S Movement Family. A Watch Collector’s Guide

Watches are no longer just accessories used for telling time. Now, they serve as worthwhile investments that showcase your status and success. They can even become great conversation starters and help you create a positive first impression.

Whether you are a newcomer to the world of timepieces or a long-time watch collector, you surely have heard of Seiko. It was founded in 1881, and it has made a name for itself as a famous brand known in many periods of time. In the 90s, it introduced 7S, which is the “mainstream automatic watch movement.” 

The 7S Family Movement

The Seiko 7S family is a widely-produced automatic watch movement. It was developed for reliability and ease of maintenance. It lacks hand-winding and hacking, but it features the Seiko Magic Lever system, which offers bi-directional automatic winding. It also returns respectable accuracy and oscillates at 21,600 A/h.

The 7S family movement is an ideal entry-level watch for new watch collectors who are on a budget. With its simple design, cost and the component count were reduced. Some parts are also made of plastic to minimize the need for lubrication.

The History

The origin of all 7S movements is a 7009 movement from the 80s, while the main movement in the mid-range was the 7000 series that was produced from the 70s to 90s. The 7S26 family was introduced in 1996 to replace the 7000 series. Until today, the 7S26 design serves as the pillar of mechanical Seiko watches and the basis for all Seiko movements from entry-level, upper mid-range, and high-end watches.

The Father of the 7S Family Movement

The Seiko 7S26 caliber inspired a whole family of Seiko movements. It is an automatic movement with accuracy ranging from -20 to +49 seconds per day and holds over 40 hours of power reserve, depending on the watch. Its operational temperature goes from 14-140 degrees Fahrenheit. It also features a Diashock system, making it resistant to even severe shocks and robust to external forces.  In addition, it operates at 21,600 beats per hour. Since it ticks six times in a second, its second hand is smoother than in quartz watches. 

This movement has three versions: 7S26A (1996), 7S26B (2006), and 7S26C (2011), and all of them have only minor changes to the mechanism. Furthermore, this movement has 21 jewels, but there is 7S36, which is a version with 23 jewels. These jewels serve as bearings for the watch mechanism’s gears. Both versions are otherwise identical aside from the additional two jewels.

A High-End Derivative

A high-end spin-off of the 7S26B movement was introduced in 2006: the 6R15. It was geared towards the upper mid-range to the high-end market. It is unique because it has a hacking function, manual winding, and a Spron 510 mainspring with a longer power reserve of 50 hours. The Spron 510 refers to alloys of cobalt, chromium, molybdenum, nickel, and other metals. It is highly durable, resists magnet, and has superb elasticity and excellent heat resistance. 


Collecting Seiko watches can be a wonderful experience. Owning high-quality watches that offer you value for your money and allow you to wear them every day for any occasion is truly remarkable. This hobby can seem intimidating, but being well-informed about the kind of watch you want to invest in is the best way to make the right purchase. Because of this, keep the information above in mind and learn more about the Seiko 7S movement as you start building your collection.

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