It seems like only yesterday that Grand Seiko expanded its Evolution 9 collection with a string of new releases during Watches and Wonders 2022. Among the new timepieces was the spectacular SBGE285 “Mist Flake,” which is one of my favorite GMT watches. This year, Grand Seiko has a smaller number of new releases for Watches and Wonders, but an absolute standout is the new Grand Seiko SLGC001 Tentagraph. This new chronograph is a new member of the Evolution 9 collection. On top of that, it’s the brand’s first all-mechanical chronograph. A Hi-Beat chronograph, to be more precise. Time to find out more.

Briefly going back to last year, I found all the new additions to Grand Seiko’s Evolution 9 collection super impressive. The way that the brand actively searched for case shapes rooted in Grand Seiko’s past and combined them with modern characteristics was spectacular. I love the exploration of shapes and sizes that gives the Evolution 9 line a modern design signature. In my opinion, Grand Seiko has succeeded in finding that signature that will be great for future releases. Let’s see how the brand’s all-new mechanical Hi-Beat SLGC001 Tentagraph aligns with that.

Grand Seiko Tentagraph SLCG001

The SLGC001 Tentagraph is not the first Evolution 9 chronograph

While the new Grand Seiko SLGC001 Tentagraph might be the first Grand Seiko all-mechanical chronograph, it’s not the very first chronograph in the brand’s history or the Evolution 9 collection. Last year, I wrote about the SBGC249 and SBGC251. These were the first Evolution 9 chronographs, and both were powered by Spring Drive movements (mostly mechanical calibers with quartz regulators). They came in a rather large 45.3mm case with a massive 52.6mm lug-to-lug. “Substantial” doesn’t even begin to cover the massive presence of these two pieces.

Grand Seiko Tentagraph SLCG001

Grand Seiko toned it down a bit this year, though perhaps not as much as people would have liked. At first glance, however, this new Tentagraph looks stunning. The case shape looks angular and modern, the combination of blue and black gives it a stylish presence, and the movement is a stroke of brilliance from Grand Seiko. But let’s zoom in on some details.

Grand Seiko Tentagraph SLCG001

It’s big, but is it too big?

The Tentagraph comes with a 43.2mm high-intensity titanium case that is 15.3mm thick. So yes, it’s a substantial timepiece. Is it too big? Honestly, my first reaction was that I would have loved to see the watch anywhere between 40mm and 42mm. Regardless, I can’t wait to see it in the metal to learn more. I can pull off a 43mm watch easily, and I am sure that the new case shape in lightweight titanium will make it a joy to wear.

To me, the looks are of equal importance, and simply put, this watch looks magnificent. The modern case is characterized by the Evolution 9’s angular lines. The right side features two two convex chronograph pushers and a screw-down crown protected by modern, faceted crown guards. The predominantly brushed finish is mixed with Zaratsu-polished bevels for extra impact. And we know that Grand Seiko is unbeatable at making a watch look good, so I’m sure this will be a stunner in reality. The Tentagraph comes with a black ceramic bezel with a white tachymeter scale. Additionally, the watch features a box-shaped sapphire crystal that completes the curvaceous overall shape. Finishing everything off is a titanium bracelet with a micro-adjustable folding clasp.

The Mt. Iwate-inspired dial

The beautiful dark blue dial of the new Tentagraph features Grand Seiko’s signature “Mt. Iwate pattern” that we have seen used for several other models. The pattern takes inspiration from the ridged contours of Mt. Iwate, which is visible from the Grand Seiko studios in Shizukuishi, Japan. This is where all Grand Seiko mechanical watches are assembled and regulated. As the dial is dark blue, it takes inspiration from the night sky above Mt. Iwate. So in good Grand Seiko tradition, this stunning new dial also has a connection to Japanese nature. While we sometimes like to poke fun at the brand’s nature references, the results are always stunning. And with this new dark blue dial, Grand Seiko has created one of my favorites, along with last year’s “Mist Flake” dial and the stunning pink dial of the Grand Seiko SBGA413.

Grand Seiko Tentagraph SLCG001

As I mentioned, the combination of the black ceramic bezel and the color of the titanium gives the watch a very stylish presence. The blue dial also has my favorite chronograph layout with three registers at 3, 6, and 9 o’clock. These sub-dials are recessed into the blue textured background, creating extra depth. Combined with the meticulously finished applied indices, it makes for a great chronograph dial. The layout features running seconds at 3 o’clock, a 30-minute chronograph counter at 9 o’clock, and a 12-hour chronograph counter at 6 o’clock. A date window with a smart black frame is neatly integrated between 4 and 5 o’clock. Just looking at the level of detail, this is an impressive dial.

Grand Seiko Tentagraph SLCG001

The Grand Seiko Hi-Beat Caliber 9SA5

Powering this new Tentagraph is Grand Seiko’s brand-new mechanical 9SA5 movement. This automatic chronograph caliber operates at 36,600vph or ten beats per second. It facilitates high accuracy both throughout the day and when measuring elapsed time. The movement comes with an energy-efficient escapement and two barrels, ensuring the watch has a 72-hour power reserve. The movement of the Tentagraph has an accuracy of +5 to -3 seconds per day, achieved over 20 days of testing. As a result, it stays well within COSC chronometer standards (+6 to -4 seconds average daily rate on the first 10 days of testing).

This chronograph movement comes equipped with a column wheel and a vertical clutch. Furthermore, it features Grand Seiko’s Dual Impulse Escapement, which transfers energy to the free-sprung balance wheel indirectly through the pallet fork and directly from the escape wheel. MEMS technology ensures extremely precise, lightweight, and highly durable escapement parts and also endows the escapement with increased energy efficiency to achieve a long power reserve. Thanks to incorporating a three-pointed hammer, the chronograph hands return to zero instantly when the reset pusher is pressed. As you can see, the movement has beautiful finishing, making it impressive in its architecture, specs, and aesthetics.

Initial impressions of the new Grand Seiko SLGC001 Tentagraph

To say I am impressed with the new Grand Seiko SLGC001 Tentagraph is an understatement. I absolutely adore the looks of this watch. The new case, the stellar dial, and the level of detail are nothing short of remarkable. Just look at the minute hand and chronograph seconds hand. They are curved for better readability, but the way it’s done is with great attention to detail. On top of that, the new Hi-Beat movement is technically and visually stunning. What a strong first mechanical chronograph caliber for Grand Seiko!

Combining all these factors makes the Tentagraph a great modern chronograph. As such, it enters the playing field that the Daytona and the Speedmaster dominate. At €14,300, it has a similar price to some of its direct competitors from other brands. Considering all the elements that make Grand Seiko — and more specifically, the Evolution 9 collection — so impressive, I have zero doubts that this is an absolute stunner in the metal. I can’t wait to see what the watch looks like up close. That will probably also eliminate my slight initial disappointment that the Tentagraph is a bit bigger than I would have liked to see. Had this been a 40mm chronograph, I would have had to save up for a second Grand Seiko after the “Mist Flake.” For now, I can only say that might be the case after I have tried it on my wrist. You and I both know where this is going…

The new Grand Seiko SLGC001 Tentagraph will be available starting in June 2023. For more information, visit the official Grand Seiko website.

Watch specifications

Dark blue with "Mt. Iwate" texture, applied indices, recessed sub-dials
Case Material
High-intensity titanium
Case Dimensions
43.2mm (diameter) × 15.3mm (thickness)
Case Back
Titanium with sapphire display window, screw-down
Grand Seiko Caliber 9SC5 — automatic chronograph movement, 36,000vph frequency, 72-hour power reserve, column wheel, vertical clutch, Dual-Impulse Escapement
Water Resistance
10ATM / 100m
High-intensity titanium bracelet with micro-adjustable folding clasp
Time (hours, minutes, small seconds), chronograph (central chronograph seconds, 30-minute counter, 12-hour counter), date
Special Note(s)
Available starting June 2023