Grand Seiko Tentagraph Iwate Sunrise SLGC006 Grand Seiko Watch Review

Hi, this is Tim of The 1916 Company. Welcome and thanks for logging on. If you love this watch, email me, timosso at the1916company.com, for purchase pricing and availability questions concerning this watch. Today, we discuss a September 2025 launch in 300 pieces made of ceramic, gold, and high-intensity titanium from Japan's Grand Seiko. This is the Tentagraph Mount Iwate. It's the SLGC-006. So, what we have here is a mechanical high-beat chronograph with the dual impulse escapement, column wheel, vertical clutch, Mount Iwate-inspired dial, and it's a plus-sized model. So, 43.2 millimeters in diameter as I measure it, 15.8 millimeters thick. We just measure the lugs, 51.2 millimeters across the wrist. We add the end links, the total horizontal distance across the wrist. It's now 53.8, and we have a 23-millimeter spacing between the lugs. We'll throw this watch on the wrist. It's a large piece. That said, it's not super heavy. It's got substance to it. It doesn't feel toy-like the way some titanium watches can, but it doesn't feel like a boat anchor either. I would argue that my wrist is either the smallest that can wear this or the largest that should not. So, I'm going to let you judge. Perspective and distance almost always helps. I do think I could wear this watch if my taste and preference were for larger sizes and styles. This would fit, sit, and probably look just fine. There's your down the barrel. There's your over the top. The watch has a lot of Evo 9 influences, and it harks back to the 2023 Tentagraph, which incredibly was Grand Seiko's first mechanical chronograph, more on that in a moment. We've got a conforming end piece, a three-link design, a little bit of a taper down towards the clasp. You can see that there's a bevel polish along the edge of the links. Because this is a Grand Seiko titanium bracelet, you can see pins and sleeves are used to fix the removable links. We've got an intermediate-sized link on each side in case you want to fine-tune the fit if you find yourself in between link sizes. Then, there's an additional set of four divots drilled into the clasp, so you can dismount the spring bar and change the anchoring point to fine-tune the fit. The clasp features satin polish and media blast. You can see a little rose gold insert with the Grand Seiko logo. We've got a thick gauge titanium swing arm. This titanium is 30% lighter than steel, as titanium tends to be. Also, more scratch-resistant than conventional 316Ls and 904L steels. We have the famed Zaratsu case polish done by Spinning Tinplate, iHand, and Craft Knowledge. It takes about three years to master this type of polish. Yes, this is a hand-finished case, and rather extensively so. One of the great selling points of a Grand Seiko watch. Taking a look at the ends of the lugs, you can see Grand Seiko is one of the few high-end brands that still expects its users to be active with their strap tools. You can easily insert your strap tool, pop that out, and put in a strap. Taking a look at the bezel, you can see this part is 18 karat rose gold. We have satin finish on the bottom and polish on the upper facet. Same rose gold used for the crown and pushers. This is a screw-down crown, as you can see from the bottom of the watch. You can see quite a bit from the bottom of the watch. The water resistance here is 100 meters. I'll verify that, just so you can see. It is a limited edition of 300 pieces. Now, the bezel insert is ceramic and it is a tachymetric scale, so you can use it to gauge the speed of a race car over a kilometer around Suzuka. Taking a look at the crystal itself, it's dramatically boxed, perhaps to give it a little bit of a vintage plexi vibe, and then we've got a dial that is designed to evoke the peak of Mount Iwate. Of course, we're familiar with all the various geography-inspired Grand Seiko dials, but it's worth mentioning that in terms of geography, it's actually two Grand Seiko studios, and this goes back to the era when Seiko watchmaking was really two companies. So you've got Quartz and Spring Drive in Nagano Prefecture, that's the Shinshu watch studio. And then you've got Morioka, which is the Shizuku Ishi studio, where the mechanical watches are made and that overlooks Mount Iwate, or perhaps I should say it overlooks the studio. And so the snow-scattered peak, along with its texture and color, is what's referenced by this dial. And the dial is described as a copper-pink dial. Okay, we'll take a look at the lume real quick so you can get a sense of how it's lumed. It's lumed quite well. It has a smooth glide, it's not Spring Drive, but it is a high beat, 5 hertz, 10 beat per second escapement. You can see we've got beautifully detailed dial with polished chapterings for each of the sub-registers, and then we've got beautifully faceted and polished and satinated individual minute and hour hands. And the same can be said for the faceting and polish of the indices. Grand Seiko hands, indices, the logo, they're cut using micrometric diamond-tipped milling tools by people who do this manually, and that is their everyday gig. The features then placed and caulked by hand. We've got a beautifully balanced dial, a couple of features worth mentioning. You can see there's a chaptering outboard that features little hashes allowing you to count one-tenth of a second. Now, that is the basis of the name Tentagraph. We have a stop seconds function. We also have a quick set. If you're not clumsy like me, you can actually find the quick set. This is the problem with having excessively manicured nails. It can be hard to use watches. There we go. As you can see, I don't have much nail. So, we've got stop seconds and we've got a quick set. Now, what we also have around back is something that's still fairly novel at Grand Seiko, which is a mechanical chronograph. So, this is based on the 9SA5. This is actually the 9SC5. It's a fairly large movement. So, it properly fills this case back. You're looking at 33 millimeters in diameter. Now, also important to mention is that it's got a 72-hour power reserve, courtesy of twin mainspring barrels. It's six position adjusted. It's accurate to no worse than minus three plus five seconds per 24 hours. We have a full balance bridge with a free sprung balance for shock resistance and precise adjustment, plus an overcoil hairspring. So, in any position, it'll keep consistent time. What you can't quite see is that there is a double impulse escapement that both directly and indirectly impulses the roller table and roller jewel of the balance. And conceptually, it's actually kind of similar to the Omega Coaxial. The finish on these is a huge step beyond previous Grand Seiko mechanical movements, and it's genuinely impressive. And we've got what appear to be little adjusters to change the end shake of the balance. And you can see those little gold screws flanking the balance bridge. That's a fascinating detail that's, in some regards, a little bit similar to what Rolex uses to allow you to adjust end shake incrementally. Now, taking another look, you can see that the bridges are beautifully executed. Everything here is mechanically decorated, but nicely done, kind of like Audemars Piguet. Though mechanical, it's worthy of a display case back. And again, it's very big, so it properly fills this case. You can see 60 joules, and it is a column wheel vertical clutch chronograph. So, the column wheel is very crisp, and the vertical clutch allows engagement with no jump, stagger, or extraneous motion, also allowing you to just leave the chrono running full-time if you wish. Now, you may ask, why did it take so long to create a mechanical Grand Seiko chronograph? Previously, they were all spring drive. Well, according to Joe Kirk, who is the expert on Grand Seiko, the reason was that previously, the company was only satisfied by the spring drive movement's ability to sustain timekeeping. With the chronograph engaged, they found that they lost too much amplitude with a conventional mechanical chronograph setup. So, previously, the chronographs were based on the spring drive. With the advent of the Twin Barrel Double Impulse 9SA5, now 9SC5 here, they finally had the ability to maintain amplitude and consistent timing, even with a mechanical drive of a chronograph complication. So, that's why they waited until they could get it right. And if you love this watch and it's right for you, reach out to Tmosso at the1916company.com for purchase and pricing details.