Review: The New Grand Seiko Tentagraph SLGC001

Pinterest LinkedIn Tumblr +

The world is a large, mysterious place and there are some facts about it that you simply can’t wrap your head around. Did you know that Japan enjoys the highest snowfall anywhere in the world, or that the word geoduck is pronounced ‘gooey-duck’? Or that there has never been a mechanical Grand Seiko chronograph, that is, until now. That last one is a shocker given how popular mechanical chronographs are amongst collectors and how long the brand has been around for. There’s always been Spring Drive chronographs within the Grand Seiko branding, or mechanical chronographs if you’re willing to go for Seiko, but never Grand Seiko mechanical chronographs.

Grand Seiko Tentagraph SLGC001

All that has finally changed this year when Grand Seiko presented the Tentagraph at Watches & Wonders. The name of the watch is a combination and play on the words that describe the timepiece: Ten – the frequency it operates in in Hz; T – for three, the number of days of power reserve; A – for automatic winding; and Graph – for chronograph. With the Tentagraph, Grand Seiko finally fills a key market gap and can now do battle with other mechanical sports chronographs in similar price brackets. Here, we bring you the details and our honest thoughts on Grand Seiko’s marquee novelty for 2023 and first ever mechanical chronograph watch.

The Case, Dial, and Hands

The Grand Seiko Tentagraph is a sizeable watch, measuring a substantial 43.2 mm in diameter and 15.3 mm in thickness. Most mechanical watches of this profile are top-heavy on the wrist, which isn’t a good thing. Fortunately, the Tentagraph isn’t like most watches. The watch is crafted in lightweight titanium which is 30% more scratch-resistant and, importantly, lighter than stainless steel. This helps to bring down the weight of the watch head. For added comfort and security, the lugs are gently curved to fit the contours of the wrist. The case is also fitted with a scratch-resistant, black ceramic bezel with a tachymeter scale – a popular design for sports chronographs these days. To round things off nicely, the case is matched with a titanium bracelet with a three fold clasp.

The Tentagraph is lighter than it looks. While it is hefty in size, its titanium body mitigates any top-heavy sensation.

As excellent as the case and bracelet for the Tentagraph are, the star of the show remains the dial. A Grand Seiko timepiece with an impeccable dial is more an expectation than a surprise to those familiar with the brand. And these dials always come with a story – the Tentagraph dial is no exception. The dial pattern here is called the ‘Mt. Iwate pattern’, named after the mountain whose peak is visible from the Grand Seiko Studio Shizukuishi. Meanwhile, the deep blue colour depicts the night sky. The combination of the pattern and colour results in some mesmerising light play – a solid choice for the brand’s first ever mechanical chronograph.

Grand Seiko dials are often a visual spectacle on their own – the Tentagraph dial is no different. While the Mt. Iwate pattern isn’t novel, it is befitting of a landmark model like the Tentagraph that aims to stand out yet not be distracting.

On the dial are three recessed sub-dials, one at 9 o’clock for chronograph minutes, another at 6 o’clock for chronograph hours and a final one at 3 o’clock for running seconds. These sub-dials lack the Mt. Iwate design and are instead adorned with a more conventional concentric guilloche pattern. To further distinguish these sub-dials, they are placed on a lower plane than the rest of the dial; the idea here is to compartmentalise and improve legibility. A date window is discreetly integrated at the 4.30 position; whether or not the practicality of the complication justifies throwing the dial slightly off-balance is a story for another day. Indicating the time are these brushed hour and minute hands with polished edges, as well as faceted hour marker appliques. These components are lumed for visibility under low-light conditions. Interestingly, while the central chronograph seconds hand is also coated with luminescent material, the other chronograph hands aren’t. The chronograph seconds hand can therefore moonlight as a running seconds hand (perks of the vertical clutch), as opposed to the petite seconde hand which isn’t treated with luminescent material.

The Movement

Driving the Grand Seiko Tentagraph is the new 60-jewel Calibre 9SC5. The movement is based on the 2020 Calibre 9SA5 that was first fitted with the ‘Dual Impulse Escapement’, an in-house developed escapement with greater efficiency than the classic lever escapement. In fact, the Calibre 9SC5 is essentially the Calibre 9SA5 with a chronograph module attached. Being a vertical clutch, column wheel chronograph, the chronograph mechanism of the Tentagraph can run indefinitely without introducing additional wear and tear to the movement. Naturally, the Calibre 9SC5 also inherits the 5 Hz frequency of the 9SA5, although, because of additional complications, it has a slightly shorter power reserve of 72 hours (vs 80 hours in the 9SA5). According to Grand Seiko, this is an industry-leading figure, which means the Tentagraph has the greatest power reserve of any ten-beat chronograph on the market today.

The Calibre 9SC5 as seen through the sapphire crystal case back

Matching the excellent specs of the Calibre 9SC5 is the equally excellent finissage applied to the movement. Compared to earlier Grand Seiko movements (that are not from the Micro Artist Studio, because that’s cheating), this new generation of movements feature a level of finishing that is more comparable to that seen in high-end Swiss watches. Of note are the polished bevels on the edges of bridges and jewel countersinks. There aren’t just your run of the mill rounded angles on the bridges, but also sharp outward angles that are that much more pleasing aesthetically and labourious to create. Other aspects that are reminiscent of Swiss movements include the Geneva wave-like decoration on the top surface of the bridges and also the numerous polished screws that are used to secure said bridges.

Barring Micro Artist Studio creations, Grand Seiko movements have generally never been this well-finished. The Calibre 9SC5 easily passes off as a high-end Swiss movement in a watch of equal or greater price.

The Competitive Landscape

It’s taken a while, but Grand Seiko finally have a true mechanical chronograph wristwatch. True to their innovative spirit, the Tentagraph is thoroughly modern (for a mechanical watch anyway) with impressive, distinguishing mechanics. And it’s not just the nitty gritty stuff that’s done well, for the brand has also redoubled its efforts on aesthetics. Not bad at all for a regular production Grand Seiko timepiece. The Grand Seiko Tentagraph SLGC001 is priced at USD13,700, offering fair value relative to competitors in the same price bracket.

The Tentagraph dominates the wrist not just due to its sheer size, but also handsome design.

Where high beat chronographs are concerned, no discussion is ever complete without mention of the Zenith Chronomaster. The variant shown in the image below is the 2022 Chronomaster Open and much like the Tentagraph, it too operates at 5 Hz. The open heart design of the Chronomaster Open aims to have the El Primero calibre’s high frequency balance wheel as prominently visible as possible. While it “only” has a power reserve of 60 hours, it is a much more compact watch compared to the Tentagraph, at 39.5 mm x 13.1 mm. Priced at around CHF9,900, the Zenith Chronomaster Open in stainless steel offers bang for buck for those in the market for a high frequency mechanical chronograph. It lacks the finnisage of the Tentagraph but it is more restrained in size and no less impressive in mechanics.

The Zenith Chronomaster Open in stainless steel

Just for the fun of it, it’s also worth mentioning the Tag Heuer Mikrotimer Flying 1000, winner of the Best Sports Watch award at the 2011 Grand Prix d’Horlogerie de Genève. The Mikrotimer is the ultimate high frequency chronograph whose blaze of glory is as intense as it is transient. The watch has two balances – a conventional one that beats at 4 Hz for timekeeping, and the other for the chronograph that beats at an absurd 3.6 million bph, or 500 Hz. When activated, it enables the Mikrotimer to measure time up to 1/1000th of a second. The catch is that the whole spectacle only lasts 150 seconds from start to finish. Only 11 pieces of the Mikrotimer were ever made and each cost over USD100,000 when it debuted.

The Tag Heuer Mikrotimer Flying 1000

Final Thoughts

As they say: “Better late than never”. Grand Seiko’s long-overdue foray into the world of mechanical chronograph watches was well worth the wait. With the Tentagraph, Grand Seiko sends a message that it means business. It may not be perfect, but when your first mechanical chronograph ever operates at 5 Hz, is well-decorated, and is very competitively priced, it is clearly a signal of intent. It is going to be interesting to see how the brand continues to build on their new mechanical chronograph line.


About Author


  1. It’s a nice watch. Saw a used one in mint condition the other day over here for around 8500US$ so next year or so these will be really cheap second hand in Japan as a tourist with the weak Yen and VAT refund.

    • Wow! That is fast!

      Its a really beautiful piece. And we thought the retail is fair value. Compare for eg with the Daytona, which retails for higher, but trading in the secondary market for far higher. I think the Tentagraph is an excellent alternative. But the market seem to favour the crown.

  2. Four you may be perfect the 4.30 affair but, aesthetics, geometry and practicality see things different. In any case and to keep you happy with the required date, let’s put it at 6 o’clock and we’ll all be 😊

    • We have to agree to disagree. I don’t feel the aesthetics of the dial is challenged by the position of the date aperture. 4:30, 3, 6 are all good. Even 12, especially if it is an outsized double date is good for my eyes. To each his own.

  3. Pingback: Review: The New Grand Seiko Tentagraph SLGC001 –

  4. That 4:30 date ruins everything !!! When you spend some serious and hard earned money you want to look at your watch and stay looking at it. Not with this Seiko. By the way, I wear my watch on my right hand and it looks to me that the entire watch industry keeps ignoring a good number of people who do the same.!!!😩😩

    • Nah, for me, the date is perfect, and required.

      How should watch companies cater to people who wear their watches on their right hand? A destro crown layout?

      Thanks for commenting.