Now available at auction from Second Vintage
This highly sought-after Grand Seiko 5646-7010 configuration represents a superb example of Japanese watchmaking from 1971. A collector favourite, this classic 56GS features a beautifully preserved gold GS medallion on the caseback and crisp case geometry. Powered by a chronometer-grade movement adjusted to five positions and temperature, and displaying both English and Kanji on its day wheel, this timepiece offers an excellent opportunity to acquire a pristine and highly legible vintage Grand Seiko.
Brand: Seiko
Model: Seiko Auto Hi-Beat
Reference Number: 5646-7010
Serial Number: 112347
Movement: Automatic, Caliber 5646 A, 25 Jewels
Dial: Clean white and silver finish with bright applied indices
Case Size: 36mm (excluding the crown)
Case Material: Stainless Steel
Production Year: 1971
Condition: Excellent vintage condition. Timegrapher: +10+12s/day, performing remarkably well.
Dial and Hands
The pristine and highly legible dial features a clean white and silver finish with no visible blemishes. Crisp, fully intact printing complements the bright, unoxidized applied indices. Positioned at three o'clock, a clean window displays the day and date, notably featuring both English and Kanji language options. The sharp and contrasting Dauphine style hands are detailed with black center stripes and present a clean finish, completely free of visible oxidation or corrosion.
Case and Crystal
The crisp and well-preserved vintage stainless steel case features sharp edges and highly defined geometry, showcasing distinct brushed lug tops alongside polished flanks. The caseback proudly displays an intact and beautifully preserved gold GS medallion. Light superficial scratches are present, remaining entirely consistent with careful wear. A polished bezel frames the face, showing only light handling marks without any deep dents or dings. The watch is fitted with a clearly signed GS crown featuring well-defined knurling. Above the dial sits a flat, clear crystal displaying no visible scratches, chips, or crazing.
Movement
Inside the case beats the automatic Caliber 5646 A, a chronometer-grade movement adjusted to five positions and temperature. The movement displays clean plates and bridges with no visible corrosion or staining, while the rotor and all visible components remain fully intact. The factory engravings proudly note twenty-five jewels alongside the adjustment specifications. Exhibiting remarkable accuracy and consistency, performing brilliantly for a vintage timepiece. The timegrapher records a rate of +10+12s/day.
Strap
The watch is paired with a classic black leather strap featuring white contrast stitching. This strap remains in excellent condition and secures the timepiece comfortably to the wrist.
Condition
Excellent vintage condition. The stainless steel case retains crisp geometry, distinct finishes, and a beautifully preserved gold caseback medallion, displaying only light superficial scratches consistent with careful wear. The dial, hands, and crystal are exceptionally clean and free of visible blemishes. The movement remains clean, fully intact, and runs strongly on the timegrapher.
Dimensions
The case measures 36mm in diameter (excluding the crown).
Remarks
This Grand Seiko offers a superb combination of sharp case geometry and an immaculate dial. The brilliantly preserved gold caseback medallion and the inclusion of a Kanji day wheel make this a highly compelling acquisition for enthusiasts of classic Japanese watchmaking.
History
The Grand Seiko 56GS series was introduced in the early 1970s and quickly became recognized for its advanced automatic movements and refined case designs. Produced by the Suwa Seikosha factory, the Caliber 56 family allowed for a slimmer case profile while maintaining the high standards of accuracy and durability expected from the Grand Seiko name. Today, well-preserved examples from this era are highly appreciated by collectors, particularly those retaining their original caseback medallions and sharp case lines.
/ Second Vintage
SKU: SEI-AHX-0001















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Seiko Grand Seiko 5646-7010 (1971)
Seiko • 1971
Sold for
€900
≈ $1,014
Sold on Sep 13, 2026
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