商品説明
This is a 1970 Grand Seiko "5646-7000".
The "56 Grand Seiko" is the final series of mechanical Grand Seikos.
It is a high-end mechanical wristwatch that achieved a slim, compact, and lightweight design while featuring a high-precision automatic movement.
Compared to the standard Ref. 5646-7010, the Ref. 5646-7000 features a rounded case design that is closer to a cushion shape.
The dial has a subtle sheen and is combined with slender hands and indices.
The movement is equipped with the "Cal. 5646A," which features a day-date display.
It includes a quick-set date and day function, a second-hand stop function (hacking), and a manual winding function.
Condition
This watch has been overhauled and its exterior refinished.
The strap has been replaced with a new genuine Seiko leather strap.
Due to aging, the entire dial has turned a shade close to champagne gold. A small brown discoloration can be seen on the 56-minute marker (near the 11 o'clock index).
The engraving on the case back remains clear, and the gold medallion is in good condition, although it shows minor scratches.
As this is a vintage watch, it is non-waterproof. Please avoid using it in environments with high exposure to moisture (such as on rainy days, while washing your face, or when perspiring heavily).
Additionally, as it is a precision instrument, please be careful to avoid strong impacts such as dropping it, and keep it away from magnetism (smartphones, PCs, speakers, bag magnets, etc.).
Cal. 5646A Operation Instructions
Manual winding: Rotate upwards in the normal crown position
Time adjustment: Rotate downwards with the crown pulled out to the second click
The second hand stops when the crown is pulled out to the second click
Quick-set date: Rotate downwards with the crown pulled out to the first click
Quick-set day: Rotate upwards with the crown pulled out to the first click (cycles in the order of English ⇒ Japanese ⇒ English)
Performing the quick-set operation while the watch displays a time between 9:00 PM and 3:00 AM will damage the calendar gears.
When using the quick-set function, please set the time to around 6:00 beforehand.
| Year of Manufacture | July 1970 |
|---|---|
| Model | 5646-7000 |
| Movement |
Automatic (with manual winding) Cal.5646A 25 jewels Vibration frequency: 28,800 bph (8 beats per second) Day/Date display (Japanese/English) Quick-set date (rotate crown downward at first click) Quick-set day (rotate crown upward at first click) Hacking function |
| Material | Stainless steel case Acrylic crystal |
| Size |
Width 36.2mm (excluding crown) Length 42mm (including lugs) Thickness 10.7mm |
| Bracelet | New Seiko strap 18mm (Cowhide/Black) Does not include GS buckle |
| Overhaul Date | Performed July 2026 |
| Condition |
Non-waterproof [Case] Scuffs and light scratches present [Case back] Scuffs and light scratches present, medallion in good condition [Crystal] Scuffs and light scratches present [Dial] Signs of aging (patina) throughout, minor discoloration near the 56-minute mark [Hands] Slight dullness present |
| Accessories | No accessories included Includes 100-day store warranty |
