The Japanese sword, known as the katana, is a world-renowned masterpiece in steel. Crafted through a distinctive and sophisticated process, the katana has created fascination and allure the world over.
Derived from nature and brought together through expert craftsmanship, the katana is made from earth, fire, water, and air. Iron sand is drawn from the earth and then heated in a furnace known as a tatara. The melted sand forms the Japanese steel, known as tamagahane.
From this Japanese steel, two variations can be found. The first is the high-carbon steel used for the outer sharp edge, or kawagane, and the second is the strong inner core of the blade, or shingane. Grand Seiko honors the katana and kawagane with the U.S.-exclusive SBGA489.
Reference Number - SBGA489
Case Material - Stainless steel
Case Back - See-through & Screw case back
Glass Material - Dual-curved sapphire crystal
Glass Coating - Anti-reflective coating on inner surface
Case Size - Diameter 40.0mm Lug-to-Lug 46.2mm x Thickness 12.5mm
Band Width - 19mm
Clasp type - Three-fold clasp with push button release
Caliber no. - 9R65
Movement Type - Spring Drive
Power reserve - Approx. 72 hours (3 days)
Accuracy - ±15 seconds per month (±1 second per day)
Water resistance - 10 bar
Magnetic resistance - 4,800 A/m
Other details / Features - Screw-down crown, 30 jewels, Power reserve indicator