Grand Seiko Heritage Hi-Beat 36000 Ever-Brilliant Steel — Spring Snowmelt Dial | Ref. SLGH013

Calibre 9SA5 represents the most significant mechanical development in Grand Seiko's history since the Spring Drive. A Hi-Beat automatic running at 36,000 vph, it introduces a dual impulse escapement that delivers energy to the balance wheel from both directions of oscillation, dramatically improving energy efficiency and reducing wear on the escapement lever. The result is an 80-hour power reserve at Hi-Beat frequency — an engineering achievement that required years of development at the Grand Seiko Studio Shizukuishi. Positional accuracy is further refined by a free-sprung balance with variable inertia, controlled by the regulation pin eliminated in favour of adjustable weights.

The SLGH013's dial evokes the snowmelt of early spring on Mt. Iwate, the 2,038-metre volcanic peak that presides over the Shizukuishi studio. As winter's snow begins to yield to the warming air, the surface takes on a luminous, layered quality — soft yet alive with reflected light. Grand Seiko's dial artisans have captured this precise moment in a light blue surface of extraordinary texture, its depth shifting with the angle of illumination. A flat dial plane combined with an expansive opening floods the surface with light, allowing razor-edged, Zaratsu-polished indices and hands to generate the intense sparkling that is the aesthetic hallmark of the Heritage Collection.

For the first time in a mainstream Grand Seiko reference, the SLGH013 uses Ever-Brilliant Steel for both case and bracelet. This high-grade alloy offers superior corrosion resistance and a brilliance that complements the Zaratsu-polished surfaces. The doubled index at twelve o'clock ensures legibility at acute reading angles. The SLGH013 is a watch in which material innovation and natural inspiration coexist with mechanical excellence.