Grand Seiko Tentagraph (SLGC001)

Pre-Owned 43.2mm Grand Seiko Tentagraph (SLGC001)

Grand Seiko’s Tentagraph SLGC001 marks the brand’s first-ever mechanical chronograph, introduced in June 2023 as part of its Evolution 9 Collection. The name “Tentagraph” cleverly combines key features: Ten (beats per second), T for its three-day power reserve, Auto, and graph for chronograph.

At its heart is the in-house Caliber 9SC5, built on the 9SA5 platform—running at 5 Hz (36,000 vph)—and thanks to a Dual Impulse Escapement plus twin barrels, it delivers a full 72-hour power reserve even with the chronograph running. This made it the longest-running 10-beat chronograph in the industry at the time of release. The movement incorporates a vertical clutch and column wheel, with meticulous finishing visible through the exhibition caseback.

The 43.2 mm case (15.3 mm thick) and matching bracelet are crafted from high-intensity titanium—around 30% lighter and more scratch-resistant than steel—and paired with a black ceramic tachymeter bezel. The textured deep blue dial features Grand Seiko’s signature Mt. Iwate pattern, inspired by the ridged contours of the mountain seen from their Shizukuishi studio. Recessed sub-dials at 3, 6, and 9 o’clock add depth and clarity, while a date window at 4:30 preserves the symmetry of the hour markers.

Accuracy is rated between –3 to +5 seconds per day, backed by a rigorous 20-day testing process that includes performance with the chronograph engaged. Despite its bold size, the titanium construction and ergonomic design help maintain comfort on the wrist.

At launch, it was priced around $13,700 and released as a boutique-exclusive model. This watch from 2023 comes complete with box and papers. The Tentagraph stands out as a technical milestone for Grand Seiko and a serious contender in the high-end chronograph category.