Grand Seiko Tentagraph - Pioneering design on the cusp of time

Not to disappoint watch enthusiasts, at the GPHG 2023 (GRAND PRIX D'HORLOGERIE DE GENÈVE 2023) event taking place in Geneva, Switzerland, one of the brand's latest designs, the Grand Seiko Tentagraph version, was nominated in the category for Chronograph stopwatches - marking another important milestone for one of the world's most precise watch manufacturers.

The Grand Seiko Tentagraph is the brand's first Hi-beat automatic chronograph. Designed by Mr. Akira Yoshida, the man behind the success of Grand Seiko thanks to his refined aesthetic, close to nature and Japanese tradition, the Grand Seiko Tentagraph is crafted based on the Evolution 9 style - the design language that has been the foundation for most of Grand Seiko's later creations.

Evolution 9 Stylewas formed based on the core elements of the “Grand Seiko Style” - the design guideline for the brand in the past. However, as time passed, the aesthetic perception of connoisseurs has also changed significantly, so the Evolution 9 Style was born to continue the traditional legacy while applying the advances of the times to current and future creations.

A distinctive feature of the Evolution 9 Style is the dial, with its redesigned hour markers and hands for maximum legibility, allowing the wearer to see the time at a glance. Every detail of the Tentagraph’s chronograph mechanism and time-of-day display has been carefully considered, from the position of the hands relative to the indices to the distance between the dial and the hands. Subdials lower than the main dial display the time of day, enhancing the depth and legibility of the Tentagraph dial. And by placing the date between 4 and 5 o’clock, Grand Seiko’s designers have ensured that the index remains at each traditional hour position while allowing maximum visibility of the time of day and chronograph subdial.

The Grand Seiko Tentagraph features a 43.2mm diameter, 15.3mm thick case and a strap made of high-strength titanium, which is approximately 30% lighter than stainless steel and more scratch-resistant, while the bezel is made of durable and extremely heat-resistant ceramic. The dial of the watch is decorated to evoke the magnificence of Mount Iwate, the soaring peak from which you can admire Grand Seiko Studio Shizukuishi, where the brand's great designs are born.

Beneath the anti-reflective sapphire crystal is a striking blue dial, with a running seconds sub-dial at 3 o’clock, a 30-minute chronograph counter at 9 o’clock, and a 12-hour counter at 6 o’clock. The hands and hour markers are coated with Lumibrite for improved nighttime legibility.

LumiBriteis a newly developed and improved fluorescent luminous paint by Grand Seiko, which quickly absorbs a larger amount of light exposed to it, glows brighter and lasts longer in the dark. This new technology is completely free of harmful substances, ensuring safety for humans and the environment. It is an ideal successor to radioactive luminous paint and conventional fluorescent paint.

The Grand Seiko Tentagraph uses a wide high-strength titanium bracelet with a five-piece link set that is fully brushed on the top – with the outside of the link pieces mirror-polished.

The Tentagraph's name describes the main features of the Calibre 9SC5 movement inside:TEn beats per second,TThree days of power reserve,Aautomatic winding, and chronographGRAPH. (Ten beats per second, three-day power reserve, automatic winding and chronograph function.)

When fully wound, the watch can run for 72 hours even with the chronograph running, making the Tentagraph the industry's longest power reserve 10-beats-per-second chronograph today.

About the Calibre 9SC5 movement - Grand Seiko's first mechanical Chronograph movement

The Calibre 9SC5 movement is crafted at Grand Seiko's facility in Shizukuishi - the same craftsmen responsible for the design and production of all Grand Seiko mechanical watches for decades. It was also here that the first 9S movement was conceived.

The designers, engineers and watchmakers at Grand Seiko Shizukuishi have two important foundations to build on. First, they inherit the tradition and accumulated know-how built up over decades of “continuous innovation” at the highest level of watchmaking. Second, as an integrated “manufacturer”, Grand Seiko has the ability to master every artistic aspect of watchmaking and has in-house control over every technical aspect of every detail of the movement.

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The hairspring in Calibre 9SC5 features a distinctive curved shape, chosen after more than 80,000 simulations, to optimize its performance in every possible position. Not only is the 9SA5 the first Grand Seiko movement to feature a free-floating balance and overcoil – hallmarks of its fine creations – it also introduces the brand’s proprietary Dual Impulse Escapement, which offers significantly improved performance compared to the common lever escapement.

A 72-hour power reserve is a respectable figure for a High-beat movement. Calibre 9SC5 achieves this through the combination of two technologies. First, the dual pulse escapement is highly energy efficient, and second, the twin barrels provide more power to the watch. Additionally, the movement’s durability is ensured by a mechanism that reduces the weight load on the front gear train. The twin barrels provide more power, allowing for a 10-beat movement with a high moment of inertia balance. Grand Seiko describes the 9SA5 as the best mechanical movement the brand has ever produced.

Being nominated at the GPHG 2023 is a huge step forward for Grand Seiko in general and Tentagraph in particular. This will be a great motivation for the brand to continue to develop on the road ahead, with many more sophisticated creations appearing in the future.