Grand Seiko adds its first mechanical chronograph to the sporty Evolution 9 line: the Tentagraph. The name is composed of the first letters of the high beat rate (ten beats per second), its long power reserve (three days), and the automatic chronograph function (automatic chronograph).

The blue dial features Grand Seiko’s signature “Mt. Iwate pattern,” inspired by the contours of the surrounding mountain of Grand Seiko’s Shizukuishi studios. The dial features a chronograph central stop seconds, a subsidiary seconds hand at 3 o’clock, a 30-minute chronograph counter at 9 o’clock, and a 12-hour chronograph counter at 6 o’clock.

The ceramic bezel sports a tachymeter scale, while the case and strap are made from Grand Seiko?s proprietary High Intensity Titanium.
The genuine Hi-Beat caliber 9SA5 serves as the platform for the new chronograph movement. Accordingly, the Tentagraph caliber 9SC5 beats ten times per second, which ensures high accuracy in measuring the elapsed time and regular timekeeping. Thanks to this energy-efficient escapement and two barrels, the watch runs for three days even when the chronograph is in operation.

As is de rigueur for the Japanese luxury brand’s modern-day developments, the caliber features a Dual Impulse Escapement, which transmits energy both indirectly via the pallet fork and directly via the escape wheel to the free-sprung balance. Grand Seiko’s MEMS technology ...