The super-precise quartz Caliber 9F, made in 1993 by Seiko for its Grand Seiko collection (years prior to the Grand Seiko spinoff) is widely considered one of the most precise quartz calibers available.
Seiko spared no expense when developing the device. The company’s pioneering quartz caliber technicians (It was Seiko that developed the first serially produced quartz watch, the Seiko Quartz Astron, in 1969) built it with a backlash auto-adjust mechanism to eliminate any shudder in the seconds hand, created a new, fast date changer and added a twin-pulse control system that gives watchmakers the opportunity to extend the minute and seconds hands to the edge of the dial. Even today, Grand Seiko grows its own quartz crystals for the series, and hand-assembles each Caliber 9F.
As a result, the caliber’s precise ±10 seconds per year precision remains among the best available, far above standard quartz rates of 10 to 15 seconds per month.
Now with GMT
As it continues to celebrate the 25th anniversary of Caliber 9F, Grand Seiko this past week expanded the collection of watches that are powered by Caliber 9F and its variations. Grand Seiko has added a GMT function to Caliber 9F, creating the new Caliber 9F86, and has announced plans to release three new 39mm steel watches powered by the new GMT movement.
One, a limited edition 25th anniversary model (SBGN001, 800 pieces, $3,500) will be available this October, utilizing a specially adjusted, higher-precision version of the movement. Two additional models, SBGN003G and SBGN005G, are permanent additions to the Grand Seiko Sport Collection and will be available in early 2019 for $3,200.
Grand Seiko says that despite the addition of the GMT hand, the case here is only slightly deeper than previous watches thanks to a newly designed main plate and a re-designed gear train. And, like the caliber’s other hands, the GMT hand is mounted on an independent axis, which helps ensure smooth operation.
For the limited edition, Grand Seiko developed an interesting metallic charcoal dial with a pattern based on the traditional symbol for quartz. That model also features the five-pointed star that symbolizes Grand Seiko’s special level precision (±5 seconds a year).
On this watch also note that at the 25-minute position Grand Seiko has commemorated its anniversary by showing the symbols 9F and 25. The steel caseback features the Grand Seiko lion emblem and a unique serial number.
Prices, as noted above: $3,500 for SBGN001, the limited edition of 800 pieces, and $3,200 for the two Sport Collection models, SBGN003G and SBGN005G.
Grand Seiko Caliber 9F86
Watch Specifications (all three)