SEIKO 70's / 56 GRAND SEIKO / Cal.5646A

Introducing the 1970 Seiko "56 Grand Seiko".

In 1960, Grand Seiko was born with the aim of creating "the finest domestic wristwatch that could compete globally."
In the latter half of the 1960s, 10-beat models such as the 61GS and 45GS were released, significantly advancing the technology of domestic mechanical watches.

Following this trend, the "56 Grand Seiko" appeared in 1970.

The 56GS pursued a thinner movement and ease of everyday use while maintaining high precision.
This series symbolizes the maturity of domestic mechanical watches, achieving a light, thin, and comfortable fit on the wrist.

■ Dial and Case Design

The "Grand Seiko Style" was established by the 44GS, released in 1967.
It is based on combining distortion-free mirror surfaces, broad flat surfaces, and clear ridges connecting them, to make the watch appear beautiful through light and shadow.

This model also inherits that design philosophy, featuring a bold flat surface on the front of the case, from which sharp lines extend towards the tips of the lugs.
The result is a three-dimensional case design that powerfully reflects light depending on the viewing angle.

The dial is silver, showing a soft luster.
Slender bar indices and linear hands are neatly arranged, and the "SEIKO" logo at 12 o'clock and the "GS" mark at 6 o'clock subtly assert its dignity as a Grand Seiko.

Despite featuring day and date displays, the overall impression of the dial is clean.
By combining a stylish case design with a refined dial, it achieves both the strong presence characteristic of the 1970s and a calm elegance that is easy to incorporate into daily life.

■ Movement

It is equipped with the automatic movement "Cal.5646A" manufactured by Suwa Seikosha.
It is an 8-beat high-beat movement operating at 28,800 vibrations per hour, using 25 jewels.

While 10-beat models with 36,000 vibrations per hour also existed in Grand Seiko at the time, the 56 series pursued a thinner movement while maintaining high precision.
The thin design, approximately 4.5mm thick, enabled a lightweight case design that fits comfortably on the wrist.

In terms of functions, in addition to manual winding and a hacking mechanism, it features a day/date display and a quick-set mechanism.
With a power reserve of approximately 46 hours, it also ensures practicality for everyday use.

The Cal.5646A is a highly refined automatic movement that did not just pursue accuracy but also achieved high standards in thinness and ease of use.
It is a highly complete Japanese automatic movement that Seiko boasted in the 1970s.

■ Styling

Case size: length 40.8mm (including lugs) / width 37.6mm (including crown) / thickness 10.3mm / weight 46g (including strap)

A neat and understated piece combining a silver dial with black leather.
It naturally complements suits and jacket styles, as well as elegant outfits like shirts and fine-gauge knitwear.

The sharp and distinctive case design provides a good accent for simple coordination.
It is also recommended for styles like a white shirt with slacks, or adult casual wear combining denim with leather shoes.

A black strap gives a sharper impression, while switching to brown or gray creates a softer, lighter atmosphere.
It is a versatile watch that retains the dignity characteristic of Grand Seiko and can be enjoyed both on and off duty.

■ Condition

The crystal has been replaced with a new genuine crystal, so it is in clear condition with no scratches or chips.
Visibility is good, allowing you to beautifully appreciate the delicate texture of the silver dial.

While there are minor scuffs on the case due to age, there are no noticeable scratches or large dents, maintaining good condition for a vintage watch.

The GS medallion on the case back is also in good condition with no noticeable wear or loss.
The movement is currently running smoothly.

■ To ensure a confident purchase

All watches handled by our store undergo internal inspection by a professional watch repair technician upon arrival, and are sold only after being authenticated as genuine, so you can purchase with peace of mind.

When you purchase a watch, we will provide a new leather strap.
Please select your desired color from the order selection tab.
*For watches with genuine straps or metal bands, the leather strap will be sent separately as a spare and not attached to the watch.
We will also send a dedicated watch case at the time of shipment.

● Important Information After Purchasing an Antique Watch, Please Read Carefully ●

At RESUME, when selling antique watches, we do not hand them over immediately upon order.
Instead, we request a complete overhaul (hereinafter OH) by a specialized craftsman, and deliver the watch after the OH is completed. (This takes approximately 1-2 months).

A specialized craftsman, certified as a Class 1 watch repair technician, will completely disassemble the watch, replace consumable parts such as internal gaskets, clean, and lubricate it.
We will thoroughly overhaul it to a state with a daily difference of approximately ±1 minute.
Additionally, upon delivery, we will send our unique OH certificate, along with photos of the watch's disassembly and maintenance during the OH process.

Of course, due to the nature of used products, there is no absolute guarantee that the watch will never break. However, we take these measures to ensure that you can enjoy the watch's original performance and use it with confidence in the future, so we ask for your understanding.

When purchasing a product, a 1-year warranty period is provided depending on the model. Even for products past their warranty period, we offer repair services for a fee.
If you do not have a repair shop nearby, please feel free to contact us.