Seiko Chronograph Slide Rule Calculator

Seiko Chronograph Slide Rule Calculator Ref. 6138-7000 (Circa 1970s) The Seiko Calculator Slide Rule Chronograph (Ref. 6138-7000) is an exceptional example of 1970s innovation and design, showcasing Seiko's commitment to precision and functionality. This watch combines the robust 6138 automatic movement with a unique bi-directional slide rule bezel, making it both a tool and a statement piece for the wrist. Rare and highly collectible, this model represents Seiko's pioneering spirit during the golden age of chronographs. Historical Significance Introduced during the 1970s, the Seiko Calculator Slide Rule Chronograph reflects the brand’s innovation and its ambition to create functional timepieces. The slide rule bezel offered practical utility for pilots and engineers, while the robust 6138 movement solidified Seiko’s reputation for reliability. The model exemplifies Seiko's transition from tool watches to horological icons during a period of global acclaim for the brand. Key Features   • Case: 44mm stainless steel case with rounded cushion shape, sharp edges, and polished finish. The case measures 44mm x 47mm, ensuring a substantial yet comfortable presence on the wrist. • Dial: Original Seiko matte black chronograph dial with contrasting yellow and white hands. Features a quickset day/date display at the 3 o'clock position. • Bezel: Original Seiko stainless steel bi-directional slide rule bezel with black enamel, functioning as an analog calculator. The recreated cursor ring, crafted by Jonathan Koch (Sweadfreak), blends seamlessly with the design. • Crystal: Original Seiko acrylic crystal, well-preserved. • Bracelet: Authentic Seiko stainless steel three-link bracelet with folding deployment clasp, completing the vintage aesthetic. • Movement: Seiko's iconic 6138 automatic chronograph movement with column wheel, featuring a quickset day/date function. Known for its reliability and precision, this is one of Seiko's most celebrated calibres.   Condition   • Case: Excellent condition with sharp edges and minimal signs of wear, retaining its original shape. • Dial: Well-preserved with no peeling or damage to the print. The applied SEIKO logo retains its mirror finish, reflecting light beautifully. • Bezel: Minimal wear, retaining its color and functionality. The recreated cursor ring enhances usability while maintaining the watch's vintage charm. • Crystal: Free of significant scratches or blemishes. • Movement: Fully serviced and in optimal working condition. • Bracelet: Excellent condition, with the clasp functioning smoothly.   Measurements   • Case Diameter: 44mm (excluding crown) • Case Length (lug-to-lug): 47mm • Lug Width: 19mm