【Product Details】
This is an authentic Grand Seiko 5645-7010 Hi-Beat 36000, one of the most iconic automatic models from Seiko’s 56GS series, produced in the early 1970s (circa 1970–1974).
The Cal.5645A movement features 10-beat (36,000 bph) precision, automatic winding with manual winding function, hacking seconds, and a quickset date mechanism — embodying the peak of Seiko’s mechanical watchmaking before the quartz era.
This piece is in excellent vintage condition (Rank 4: Very Good) and is fully functional.
The silver sunburst dial remains bright, with crisp printing and minimal signs of age. The gold GS medallion on the case back is well preserved.
✅ Cal.5645A / Hi-Beat 36,000 vibrations per hour
✅ Automatic winding + manual winding
✅ Hacking seconds function
✅ Quickset date function
✅ Made in Japan (Daini Seikosha / Kameido)
✅ Running condition confirmed
✅ Automatic and manual winding – smooth operation
⚙ Cal.5645A / 25 jewels / Hi-Beat 36,000 bph
⚙ Date display with quickset
⚙ Hacking seconds (stops when setting time)
⚙ Currently running normally
⚠ Accuracy not guaranteed due to vintage nature
| Item | Details |
|---|---|
| Brand | Grand Seiko |
| Model | 5645-7010 |
| Movement | Automatic (Cal.5645A / 36,000 bph) |
| Case Material | Stainless Steel |
| Bracelet | Stainless Steel (aftermarket) |
| Case Size | Approx. 36.5mm (excluding crown) |
| Lug Width | 18mm |
| Thickness | Approx. 11mm |
| Dial | Silver sunburst |
| Crystal | Domed acrylic |
| Crown | SEIKO original |
| Wrist Size | Approx. 16cm (adjustable with extra links) |
| Water Resistance | Not guaranteed |
| Country of Manufacture | Japan (Daini Seikosha) |
| Year | Early 1970s |
| Condition Rank | 4 / Very Good (Minor signs of wear) |
✅ Movement: Runs properly (tested, duration not measured)
✅ Dial: Beautiful silver tone, clean with minimal aging
✅ Case: Excellent vintage condition with light scratches
✅ Crystal: Clear with faint surface marks
✅ Back: Gold GS medallion in good preserved condition
✅ Bracelet: Stainless steel, aftermarket, good condition
⚠ Accessories: None (watch only)
| Part | Grade | Notes |
|---|---|---|
| Movement | A– | Working, stable operation |
| Case | A– | Light aging only |
| Dial | A | Clean and elegant |
| Crystal | B+ | Small surface marks |
| Bracelet | A– | Aftermarket stainless steel |
| Overall | A– (Excellent Vintage Condition) |
✅ USA Buyers: DDP (Delivered Duty Paid) — Import duties & taxes INCLUDED
🌍 Other Countries: Import duties and taxes are the buyer’s responsibility.
✈️ Ships from Japan via FedEx / DHL with tracking and insurance.
The Grand Seiko 5645-7010 marks the final chapter of the mechanical Grand Seiko era before the transition to quartz.
Equipped with Seiko’s in-house Cal.5645A Hi-Beat 36,000, it reflects both precision and practicality, housed in a thin, modern case that defined 1970s Japanese design.
The clean silver dial, angular lugs, and gold medallion emblem are timeless symbols of Grand Seiko’s pursuit of perfection.
This example, in running and well-preserved condition, represents an excellent opportunity for collectors worldwide.
💡 Tips for Collectors:
56GS = thinner and more practical than 61GS.
Cal.5645A includes hacking seconds and quickset date.
Represents the last mechanical Grand Seiko before the quartz revolution.
Early models with gold medallion are increasingly rare.