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