Grand Seiko Release Their First Hi-Beat ‘Tentagraph’ Chronograph

If Grand Seiko’s claim that the new Tentagraph is their first mechanical chronograph has made you wonder what on Earth the Evolution 9 Chronograph was all about, it’s simple. They’re not counting Spring Drive as mechanical. After all, Spring Drive movements feature quartz regulators, so while they’re mechanically powered, it’s technically true.

The new Tentagraph on the other hand is hi-beat, a more traditional form of calibre with an incredibly high frequency. The exact movement is actually a new one called the Tentagraph Calibre 9SC5, which is based on the hi-beat 9SA5.

It’s an automatic chronograph movement with a three-day power reserve and a frequency of ten beats per second or 36,000vph. If you take some of the letters from those specs – TEN beats, Three days, Automatic chronoGRAPH – you get the name Tentagraph.

It has a 43.2mm diameter titanium case with the Evolution 9’s sporty design with angular, facetted lugs. The broad ceramic bezel features a black tachymeter, contrasting with the rich blue of the dial and its recessed, tricompax subdials. At first glance, the dial may appear to have a sunray brushed finish, but it’s actually Grand Seiko’s Mt. Iwate pattern with a subtle ridge texture that’s really lovely.

In comparison to the Evolution 9 Spring Drive Chronograph, I definitely prefer the Tentagraph. The layout of the subdials is much nicer with the 30-minute timer, small seconds and 12-hour timer spread evenly across the dial instead of the asymmetrical layout seen on the Spring Drive edition. Plus, the Tentagraph doesn’t have a GMT function, which over-complicated the display of the other.

The Grand Seiko Tentagraph is priced at £12,500, making it one of the most expensive non-precious metal watches in the Grand Seiko stable. It’s also, unusually, around £2,000 higher than the Spring Drive equivalent. But for a watch as nice as this, that difference is negligible.