Introducing Grand Seiko’s first mechanical chronograph, the ‘Tentagraph’

With a dial inspired by the ridges of Mount Iwate, the brand’s latest meticulous movement is at the heart of its new titanium timepiece…

There is a vast, glass room in Grand Seiko’s Studio Shizukuishi that gazes out upon the Ōu range’s highest peak; Mount Iwate. But Iwate isn’t a mountain at all; it’s a volcano — as dramatic and dynamic as the timepieces that tick to life in the prefecture’s premier watchmaking studio.

It’s also the inspiration behind the Japanese brand’s signature ‘Mt. Iwate’ dial pattern, a contoured texture designed to evoke the ridgelines of the magnificent mountain. And the latest watch to feature this trademark finish is the new ‘Tentagraph’, the first mechanical chronograph in Grand Seiko’s ‘Evolution 9’ collection.

In a gentle dark blue hue — a colour specifically chosen to evoke the inky night skies over Mount Iwate — the Tentagraph has perhaps the watchmaker’s most legible dial yet. Hand-assembled in the nearby Shizukuishi Studio, it features subtly downward-curving minute and chronograph seconds hands, the tips of which bend closer towards a watch’s markers and indexes than any Grand Seiko ever before — and thus allow the wearer to tell the time even more accurately.

Those bowed hands, and the newly enlarged indexes, are also coated with lashings of ‘Lumibrite’ — further enhancing readability, even in low light. And this glint and glow doesn’t end outside of the watch’s dial. Hewn from high-intensity titanium, the Tentagraph’s ‘Zaratsu’ polished case is finely graded to create sharp ridges between its mirrored and hairline surfaces, and a distortion-free finish gives any more polished portions a superior shine.

Encircling the blue dial, the Tentagraph’s bold ceramic black bezel offers a deep counterpoint to the glowing titanium case, and also helps to protect the timepiece from any accidental scrapes or scratches. It’s a similarly preventative story with the titanium itself; a metal that may be around 30% lighter than stainless steel — but is almost doubly durable.

It makes for the perfect sporting metal. And this titanium extends beyond the case, linking onto the three-fold clasp bracelet and ensuring a lightweight, unobtrusive presence on your wrist. In fact, everything from the curved profile and wider lugs to the Tentagraph’s low centre of gravity combine to give the wearer unprecedented levels of ergonomics and everyday comfort.

Turn the Tentagraph over, and you’ll find a break from this titanium construction — with a sturdy sapphire caseback offering a glimpse at the beautiful finishing of the movement; the ‘Tentagraph Calibre 9SC5’.

It’s a mechanism befitting such a sporty, trailblazing timepiece; building on the revolutionary ‘Hi-Beat Calibre 9SA5’ with an energy-efficient escapement and two barrels. These extras ensure that, despite beating ten times per second, this watch will run for three days — even when the chronograph is in operation. That gives the Tentagraph the largest power reserve of any 10-beat chronograph across the entire industry. Another world first for Grand Seiko.

And this market dominance is the product of a rigorous, elongated testing process. To make certain that the Tentagraph was up to the Grand Seiko standard (+5 to -3 seconds per day), this new model had its time-of-day accuracy assessed in six different positions, and at three temperatures, over 17 days. Following this, three more days of testing were carried out — with the chronograph function running.

From a vertical clutch — which eliminates any shuddering or jumping of the hands when the chronograph is engaged, to a column wheel — which ensures precise control of the function, the watch bears every hallmark of a high-quality modern chronograph. But, despite its many talents, these functions are displayed tidily. You’ll find a small running seconds dial at the three o’clock position, a 30-minute chronograph counter at nine and a 12-hour chronograph counter at six. It’s meticulously, legibly laid-out.

And this attention to detail extends to the Tentagraph’s name. A tightly choreographed blend of acronym and description, the ‘TEN‘ is a nod to those ten beats per second, the ‘T‘ signifies the three-day power reserve, the ‘A‘ stands for ‘automatic’ and the ‘GRAPH‘ for ‘chronograph’. It’s a smart name; one that sounds as if it could have been cooked up and coined by historic horologists — but still tells us exactly what this modern Grand Seiko is capable of.

Not that we were ever in doubt. The Japanese company has quietly, confidently become one of the most exciting watchmaking brands working today — developing in tune with nature, taking creative cues from the great outdoors and sitting studiously and innovatively in the shadow of the great, majestic and endlessly inspiring Mount Iwate. The Tentagraph is simply the latest to arrive.

Grand Seiko Tentagraph

Grand Seiko Tentagraph

£12500.00

Buy Now

The Tentagraph will be available in Grand Seiko boutiques in June 2023. Discover the New Bond Street boutique here…

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