Grand Seiko Tentagraph - Pioneering design at the pinnacle of time.

Not wanting to disappoint watch enthusiasts, at the GPHG 2023 (GRAND PRIX D'HORLOGERIE DE GENÈVE 2023) event currently taking place in Geneva, Switzerland, one of the brand's latest designs, the Grand Seiko Tentagraph, has been nominated in the Chronograph category – marking another significant milestone for one of the world's most accurate watch manufacturers.

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

Evolution 9 styleIt was formed based on the core elements of the "Grand Seiko Style" - the guiding principle of design for the brand in the past. However, over time, the aesthetic sensibilities of watch enthusiasts have changed significantly, so the Evolution 9 Style was created to both continue the traditional legacy and apply the advancements of the era to current and future creations.

A defining feature of the Evolution 9 Style is its dial, with redesigned hour markers and hands for maximum readability, allowing the wearer to tell the time at a glance. Every detail of the chronograph mechanism and the Tentagraph's time-of-day display has been meticulously calculated, from the position of the hands relative to the indices to the distance between the dial and the hands. Sub-dials positioned below the main dial display the time of day, enhancing the depth and readability of the Tentagraph dial. And by placing the date between 4 and 5 o'clock, Grand Seiko's designers ensured the indices remained at their traditional hour positions while allowing maximum visibility of the time of day and the chronograph sub-dials.

The Grand Seiko Tentagraph boasts a 43.2mm diameter, 15.3mm thickness case, and a bracelet made of high-strength titanium, which is approximately 30% lighter than stainless steel and more scratch-resistant. The bezel is made of durable, heat-resistant ceramic. The dial is adorned with imagery reminiscent of Mount Iwate, the towering peak from which the Grand Seiko Studio Shizukuishi, the birthplace of the brand's greatest designs, can be admired.

Beneath the anti-reflective sapphire crystal lies a striking blue dial, featuring a sub-dial for the running seconds at 3 o'clock, a 30-minute counter at 9 o'clock, and a 12-hour counter at 6 o'clock. The hands and hour markers are coated with Lumibrite to improve visibility at night.

LumiBriteThis is a new and improved fluorescent phosphorescent paint developed by Grand Seiko, which quickly absorbs a larger amount of light upon contact, glowing brighter and longer in the dark. This new technology is completely free of harmful substances, ensuring safety for humans and the environment. It is the ideal successor to conventional radioactive phosphorescent paints and fluorescent paints.

The Grand Seiko Tentagraph uses a wide, high-strength titanium bracelet with five fully brushed links on the top – with the outer edges of the link pieces mirror-finished.

The name Tentagraph describes the key characteristics of the Calibre 9SC5 movement inside:TEn beats per second,Tthree days of power reserve,Aautomatic winding, and chronoGRAPH(Ten beats per second, three-day power reserve, automatic winding, and stopwatch function.)

When fully wound, the watch can operate for 72 hours even with the chronograph function active, making the Tentagraph the longest-power-reserve 10-beat-per-second chronograph in the industry today.

A brief overview of the Calibre 9SC5 movement - Grand Seiko's first mechanical chronograph movement.

The Calibre 9SC5 movement is manufactured at Grand Seiko's Shizukuishi facility – where the craftsmen responsible for designing and producing all Grand Seiko mechanical watches for decades have also been responsible. It is also here that the first 9S movement was conceived.

The designers, engineers, and watchmakers at Grand Seiko Shizukuishi rely on two key foundations. First, they inherit a tradition and accumulate expertise built 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 possesses internal control over every technical aspect of each component in the movement.

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The hairspring in the Calibre 9SC5 movement features a unique curved shape, selected after over 80,000 simulations, optimizing its performance in every possible position. The 9SA5 is not only the first Grand Seiko movement to feature free-balance and an overcoil hairspring – a hallmark of exquisite timepieces – but it also introduces the brand's proprietary Dual Impulse Escapement, delivering significantly improved performance compared to the common lever escapement.

A 72-hour power reserve is impressive for a high-beat movement. The Calibre 9SC5 achieves this through a combination of two technologies. First, a high-energy-efficiency dual escapement, and second, a double mainspring that provides more power to the watch. Furthermore, the movement's durability is ensured by a mechanism that reduces the load placed on the front gear train. The double mainspring provides more power, allowing for 10 beats per minute with a large moment of inertia. Grand Seiko describes the 9SA5 as the best mechanical movement the brand has ever produced.

Being nominated at GPHG 2023 is a significant step forward for Grand Seiko in general and the Tentagraph in particular. This will be a huge impetus for the brand to continue developing on its path forward, with many more exquisite creations appearing in the future.