Cal. 52 is a column wheel chronograph movement produced by Landeron in the 1940s and 1950s. It was a higher-end movement with 17 jewels and two chronograph pushers. Production is said to have started in 1942 and ended around 1955.
Seiko 9SA5
Cal. 9SA5 is the first movement in the new Hi-Beat 80 Hours 9SA series from Grand Seiko. It is a slim but oversized automatic movement with date. Cal. 9SA5 was introduced in 2020 in the Grand Seiko 60th Anniversary, Ref. SLGH002.
Seiko 9SA Family
The 9SA family movements operate at 36,000 A/h (10 Hz) yet achieve 80 hours power reserve thanks to precision materials and a novel double-impulse escapement. This escapement, similar to George Daniels famed Coaxial design, is paired with a free-sprung balance, a first for Grand Seiko. The movement wheel train is entirely new as well, designed so all of the gears sit are in a single plane, reducing movement thickness. This is possible thanks to a larger 31.86 mm diameter, up from 28.40 mm in previous Grand Seiko movements.
| Calibre | Jewels | Functions | Models |
|---|---|---|---|
| Cal. 9SA5 | 47 | Date | SLGH |
Seiko 9SA Family
Introduced in 2020, the 9SA family of movements are the next generation “Hi-Beat” movement from Grand Seiko. Following on the Seiko 9S8 family of Hi-Beat movements, this family includes numerous improvements, including an 80 hour power reserve. Other advances include a new dual-impulse escapement, the implementation of a free-sprung balance, and a redesigned horizontal gear train.
Specifically, Seiko highlights the following advances in the 9SA series:
- Dual Impulse Escapement – Seiko’s new escapement features a three-pointed anchor similar to the George Daniels/Omega Coaxial or Audemars Piguet three-pallet escapement. This transmits power directly to the balance in one direction and through the pallet fork in the other. These components are manufactured using MEMS technology for extreme precision.
- Free-Sprung Balance – Seiko adopts a free-sprung balance with an overcoil, similar to those used by other high-end watchmakers. The shape is unique to Seiko. The balance wheel also has a new square notched profile with square headed screws for adjustment.
- Horizontal Gear Train – The gear train was redesigned to place all components on the same plane, resulting in a slimmer profile. The movement also adopts a balance bridge design not previously seen in a Seiko calibre.
Seiko 9SA Family
The 9SA family movements operate at 36,000 A/h (10 Hz) yet achieve 80 hours power reserve thanks to precision materials and a novel double-impulse escapement. This escapement, similar to George Daniels famed Coaxial design, is paired with a free-sprung balance, a first for Grand Seiko. The movement wheel train is entirely new as well, designed so all of the gears sit are in a single plane, reducing movement thickness. This is possible thanks to a larger 31.86 mm diameter, up from 28.40 mm in previous Grand Seiko movements.
| Calibre | Jewels | Functions | Models |
|---|---|---|---|
| Cal. 9SA5 | 47 | Date | SLGH |
Seiko 6890
Cal. 6890 is an ultra-thin hand-winding two-handed movement produced by Seiko for Credor since 2009. Although derived from the 1969 Cal. 68A, Cal. 6890 and other recent movements in the Cal. 68 family (Cal. 6898, 6899, and 6830) are quite different in design and execution. Notably, the balance wheel is moved opposite the winding crown thanks to the round rather than squared-off shape of the movement, and the bridges are redesigned for more graceful appearance.
Seiko 68 Family
Seiko 6898
Cal. 6898 is an ultra-thin hand-winding movement with small seconds produced by Seiko for Credor since 2005. Although derived from the 1969 Cal. 68A, Cal. 6898 and other recent movements in the Cal. 68 family (Cal. 6890, 6899, and 6830) are quite different in design and execution. Notably, the balance wheel is moved opposite the winding crown thanks to the round rather than squared-off shape of the movement, and the bridges are redesigned for more graceful appearance.
Seiko 68 Family
Seiko 6899
Cal. 6899 is an ultra-thin hand-winding skeleton movement produced by Seiko for Credor since 1996. Although derived from the 1969 Cal. 68A, Cal. 6899 and other recent movements in the Cal. 68 family (Cal. 6890, 6898, and 6830) are quite different in design and execution. Notably, the balance wheel is moved opposite the winding crown thanks to the round rather than squared-off shape of the movement, and the bridges are redesigned for more graceful appearance.
Seiko 68 Family
Seiko 6830
Cal. 6830 is an ultra-thin tourbillon movement from Seiko’s Credor brand. Hand-built at the Shizukuishi Watch Studio, it is part of the Seiko 68 stream of ultra-thin movements dating back to 1969. Seiko claims that it is the smallest tourbillon movement by volume ever produced, though it is not the thinnest. It was introduced in 2016 at BaselWorld in the FUGAKU limited-edition watch, Ref. GBCC999.
Cal. 6830 is a notable achievement for Seiko, being the first tourbillon movement ever produced by the company and one of the smallest such movements. But it is also notable in other ways. It contains just 22 jewels, a small number in a field where jewel count is often exaggerated and emphasized. It also contains just 153 components, a very small number for such a complex movement. It is also hand-built by a single watchmaker, and produced by a small team named by Seiko in their press releases. Finally, it is a very traditional movement, tracing its roots back to 1969’s Cal. 68A, and does not include many modern elements or technologies.
- 2016 Credor Fugaku GBCC999 (Limited Edition of 8 pieces at 50 million Yen)
- 2017-present Credor Masterpiece GBCC997
- 2017-present Credor Masterpiece GBCC996
Seiko 68 Family
Seiko’s 68 stream is a family of ultra-thin hand-winding watch movements produced since 1969. Originally created by Daini Seikosha, the descendants of Cal. 68A continue in production as of 2020 and remain an impressive technical accomplishment.
All members of the Cal. 68 family operate at 21,600 A/h and have a 37 hour power reserve. All are regulated to -15/+25 seconds per day accuracy.
The original Cal. 68A was only produced for a short time following its 1969 introduction, but Cal. 6810 lasted all the way to 1978. It was squared off at the sides for a near-tonneau shape. This fit in the square and rectangular watches that were popular at the time.
This would have been the end of the Cal. 68 family if Seiko had not brought the movement back into production in 1991 for a special limited-edition “U.T.D.” watch for the 110th anniversary of the company. It re-entered regular production by 1993, continuing in use in the simple SCVL series until 1998.
Also in 1993, a new updated version was introduced, Cal. 6870, with better finishing for use in Credor watches. Although still hand-built, the future 68 series would be focused on this high-end brand.
In 1996, the skeletonized Cal. 6899 was released, with a complete redesign. For the first time since 1969, the movement was round. This allowed the balance to be relocated opposite the winding stem, and the bridges were completely changed. All future versions of the movement would use this new architecture. Cal. 6898 is the next to appear in the catalog, bringing a small seconds subdial in 2005. Next came Cal. 6890, a simple movement with no running seconds, in 2009.
The newest member of the Cal. 68 family is perhaps the most important. Introduced in 2016, Cal. 6830 is Seiko’s first tourbillon. Replacing the balance at 9:00 on the dial, the tourbillon includes many innovations to be constructed so thin and with so few parts.
Seiko 68 Family
Seiko 6L35
Cal. 6L35 is a high-end slim automatic movement with date from Seiko. Produced only in 2018, it part of the earlier Seiko 4L/6L family which provided the design for the Soprod A10 family of Swiss movements. It is exactly the same size as the popular ETA 2892A2, and has similar specifications as well, though the design is completely different. It is similar to Cal. 4L25 and 4L75.
This movement does differ slightly from its predecessors. It has an extra jewel, now 26, and has switched from double-cone Incabloc shock absorbers to Seiko’s own three-sided Diafix. It is also rated for 45 hours power reserve, compared to 42 hours for the previous movements.
Cal. 6L35 has only been used in a single watch model:
- 2018 Seiko Presage SARA015/SJE073J1 (Limited Edition of 1,881 examples)
- Seiko Presage SJE075, SJE077, SJE079, SJE081
Seiko 4L/6L Family History
The Seiko 4L/6L movement family is extremely rare, having only appeared in three versions in upscale and rarely-seen watches. The first member of the family, Cal. 4L25, was listed in the Seiko catalog from 2006 through late 2008 in the SARA watch line. Cal. 4L75, an upscale version, appeared in 2007 in the Credor Signo and Node lines and was retired in 2013. These differed only in accuracy (-15/+25 vs. -10/+15) and finishing. The movement returned in 2018 as Cal. 6L35, briefly used in a limited-edition Presage model, before returning to full production for Credor’s GCCD line in 2019 as Cal. 6L75.
There is no question that Seiko was working on this movement much earlier, however. It was talked about in the early 2000s, and Soprod began using the design as the basis for their Alternance 10 family in 2004. The movement continues to be produced by Soprod as Cal. M100, making it likely that far more Swiss offspring have appeared than Seiko-branded models.
Seiko 4L75
Cal. 4L75 is a high-end slim automatic movement with date from Seiko. Produced from 2007 through 2013, it was part of the Seiko 4L/6L family, which was similar in design to the Soprod A10 family of Swiss movements. It is exactly the same size as the popular ETA 2892A2, and has similar specifications as well, though the design is completely different.
Cal. 4L75 differs from the preceding Cal. 4L25 in details of finishing and regulation. Both have the same specifications, features, and dimensions.
Cal. 4L75 was used in two Seiko Credor models in the Signo and Node family:
- 2007-2012 Credor Signo GCBW999
- 2007-2011 Credor Signo GCBW997
- 2008-2011 Credor Signo GCBW995
- 2008-2011 Credor Signo GCBW993
- 2008-2012 Credor Node GCBW991
- 2008-2013 Credor Node GCBW989
Seiko 4L/6L Family History
The Seiko 4L/6L movement family is extremely rare, having only appeared in three versions in upscale and rarely-seen watches. The first member of the family, Cal. 4L25, was listed in the Seiko catalog from 2006 through late 2008 in the SARA watch line. Cal. 4L75, an upscale version, appeared in 2007 in the Credor Signo and Node lines and was retired in 2013. These differed only in accuracy (-15/+25 vs. -10/+15) and finishing. The movement returned in 2018 as Cal. 6L35, briefly used in a limited-edition Presage model, before returning to full production for Credor’s GCCD line in 2019 as Cal. 6L75.
There is no question that Seiko was working on this movement much earlier, however. It was talked about in the early 2000s, and Soprod began using the design as the basis for their Alternance 10 family in 2004. The movement continues to be produced by Soprod as Cal. M100, making it likely that far more Swiss offspring have appeared than Seiko-branded models.