The Japanese sword, known as the katana, is a world-renowned masterpiece in steel. The distinctive and sophisticated process of crafting the katana, coupled with its superb functionality, has created a fascination and allure worldwide. This art form has inspired three new US-exclusive Grand Seiko creations influenced by the materials and craft that reflect strength, perseverance, and beauty of the katana.
The katana derives from nature but can only come to be through craftsmanship. The raw materials used in its creation are earth, fire, water, and air. Iron sand is drawn from the Earth and then heated using fire and air in a furnace known as the tatara. The melted sand forms the Japanese steel known as tamahagane. From tamahagane, two variations can be found. One is the high carbon steel used for the outer sharp edge, known as kawagane. The other is the strong inner core of the blade, shingane. The shards of metal are then stacked individually; heated to a glowing yellow, orange, and red color; forged; folded; and quenched in water until the inner core is welded within the hardened exterior. Forming the katana is a demanding and exacting art, yet it creates the foundation of a perfectly balanced and beautiful sword.
Polishing the katana involves handcraft of tremendous skill and dexterity. The same can be said of crafting a case for Grand Seiko through Zaratsu polishing, particularly the 44GS design, which established the Grand Seiko Style in 1967. Only skilled and experienced hands can refine the shape of the blade or the watch case, using a flat, hard, and abrasive surface to polish surfaces and help to form distinctively sharp edges, multiple intersecting planes, and a perfect mirror finish.
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The hardness and beauty of kawagane inspire the black dial of SBGA489, and the resilience and strength of shingane are represented in the dark green dial of SBGA491. The dial pattern evokes the unique texture in the variations of tamahagane, the “jewel” steel from which traditional katana swords are fashioned.
A Limited Edition of 500 for reference SBGA493, inspired by the forge uses a unique dial pattern within the series. While still inspired by the katana, the SBGA493 expresses the determination and fiery spirit needed to craft the blade. The deep red color with yellow gold-tone accents is influenced by the heated blade during the forging process. The pattern emulates the radiating sparks created when the hammer strikes the blade.
All three models are made of stainless steel and measure 40mm in diameter, 12.5mm in thickness, and 46.2mm in length. Each features a stainless steel bracelet with a three-fold clasp, a dual curve sapphire crystal, and an exhibition case back revealing the Spring Drive Automatic Caliber 9R65. Caliber 9R65 has a power reserve of
72 hours, 30 jewels, and an accuracy of ±1 second per day (±15 seconds per month).
Models SBGA489 and SBGA491 will be available starting this August, and SBGA493 will be available beginning this September. All three models will be available exclusively at Grand Seiko Boutiques, the Grand Seiko Boutique Online, and select Grand Seiko Authorized Retailers operated in the US.
 SBGA489 |  SBGA491 |  SBGA493 |
Grand Seiko Heritage Collection
44GS USA Exclusive
Spring Drive Caliber 9R65
Driving system: Automatic
Power reserve: 72 hours
Accuracy: ± 1 second per day (± 15 seconds per month)
Number of jewels: 30
Specifications
Stainless steel case
Stainless steel bracelet with three-fold clasp and push-button release
Kimono fabric strap included (SBGA493)
Dual-curved sapphire crystal with anti-reflective coating
See-through screw case back
Water resistance: 10 bar
Magnetic resistance: 4,800 A/m
Diameter: 40.0 mm, Thickness: 12.5 mm
Limited edition of 500 (SBGA493)
source : Grand Seiko News