The concept of Grand Seiko was born from the desire to build the world's best watch, and the collection continues to push precision in mechanical watches to the limits of timekeeping technology.

As a true manufacture, Grand Seiko incorporates the latest technology alongside its breadth of craftsmanship to raise the art of watchmaking to its peak.

With anywhere between 200 and 300 individual parts, mechanical watches must exhibit a near-perfect consistency of functionality in the detail of these parts to ensure the precision of the movement. Seiko employs Micro Electro Mechanical Systems (MEMS) technology in the manufacturing of its escapements, bringing the mechanical accuracy of its parts to the forefront of technology.
Mere parts alone, however, cannot constitute the level of precision for which Grand Seiko is renowned.

The task of assembling Grand Seiko is borne by craftsmen and women who have honed their craft to such an extent that they can adjust parts by hand to tolerances of one hundredth of a millimeter. This extremely detailed craftsmanship is what has made possible the very precise timekeeping delivered by the 9S mechanical movement.


Mechanical watches utilize an escapement, a self-contained www.ce that draws its power from the motive force of a mainspring and uses the same power to regulate the speed at which the spring unwinds. It is a system which has remained largely unchanged since moving hands were first used to tell time.


As part of the mechanism, a wound-up mainspring exerts force to turn gears at a set speed as it unwinds. The precision of the system as a whole is dictated by this speed and the escapement mechanism, comprising the balance, pallet fork, and escape wheel.


The pallet fork sets the pace for the revolving escape wheel and it, itself, operates in accordance with the oscillating balance.


The balance rotates back and forth like a pendulum, ensuring that the mainspring unwinds at an even speed and over an extended period of time. In doing so, the balance effects the steady rotation of the hour, minute, and second hands.


Adjusting the hairspring – the key to precise timekeeping

The hairspring is the core component at the heart of a mechanical watch which governs its precision.

The elegantly coiled hairsprings are akin to living creatures, with an individuality all their own. Our craftsmen and women can identify and work with this variation, inserting pincers into the spaces within the coil to make adjustments by hand with a precision of one hundredth of a millimeter.

The beautiful ripple-like vibrations of a properly adjusted hairspring are enough to bring a smile to the face of any craftsman. To see the spring come alive is to witness the birth of a mechanical watch and the watchmaker’s work transcends manufacturing to become a work of art.


The balance wheel
– a pillar of precision

The balance wheel serves the important role of ensuring a consistent beat. The part is so critical to the overall precision of every Grand Seiko watch that its weight is adjusted to within tolerances of one ten thousandth of a gram.

Because it is so sensitive, even the slightest temperature change can cause it to expand or contract, potentially leading to distortions in shape.

The 9S mechanical movement minimizes effects of temperature on the balance wheel and preserves overall precision by adding a fourth arm over the usual two or three.

While this attention to detail increases the level of work required in the manufacture of components, Seiko is committed to preventing balance wheel deformation and maintaining ultimate precision.


Polished by hand

The power must flow between the gears with only minimal loss of energy to assure that the watch performs perfectly over time.

To ensure the efficient transfer of the critical power of the mainspring, Seiko’s craftsmen and women polish the grooves between the gear teeth one by one.

The painstaking but vital polishing of every gear tooth ensures that friction is minimized and that the longevity of every component is extended.

MEMS technology for high precision parts
Micro-Electro-Mechanical Systems (MEMS) technology is used to fabricate precision parts for Caliber 9S. MEMS, a highly advanced semi-conductor manufacturing technology – makes it possible to produce lightweight parts with extreme precision to tolerances of one thousandth of a millimeter.
  • Escape wheel teeth tips designed for greater retention of lubrication

    1. Escape wheel

    Escape wheels manufactured using MEMS technology are 5% lighter than others, which is important as it means that less power is required to turn them and the power reserve is longer.

    MEMS also makes possible greater lubricant retention, even at the higher rotation speeds of a high-beat movement, which increases the durability of the escapement.

  • 2. Pallet fork

    Pallet forks manufactured through MEMS achieve a 25% weight reduction due to a change in raw material.
  • 3. Hairspring

    We have more than 50 years of manufacturing experience and know-how in the making of alloys for springs. In 1964, a new material was created, which was later called “Spron”. Spron is a cobalt-nickel alloy, and it has superior elasticity, great strength, and high heat and corrosion resistance. For the www.lopment of the hi-beat caliber 9S85, a new Spron alloy was created. Released in 2009, it had taken five years but the result was worth the wait. The “Spron 610” in the new hairspring was more resilient to shock and magnetism and ensures stable accuracy.

    By transitioning to this exceptionally hard material, the new hairspring is able to tolerate greater impacts and ensure the precision, minimizing error due to changes in position.

  • 4. Mainspring

    With the reinforced mainspring www.loped for the 10 beat Caliber 9S85, Grand Seiko achieved the level of torque necessary for a power reserve of up to 55 hours.

Quality control for the highest standard of accuracy

Precision beyond that of a chronometer

The first Grand Seiko, produced in 1960, was awarded official designation as a 'chronometer' according to the highest chronometer standard of the time. It carried the word ‘Chronometer’ on the dial.

Today’s Grand Seiko watches, however, no longer carry this designation because, in the 1970’s Grand Seiko introduced its own, higher, standard. The latest version of this standard, the New GS Standard, was established in 1998 and set standards more stringent than any other.

Some specially adjusted versions of Caliber 9S hold an even greater distinction. Designated with the ‘Grand Seiko Special Standard’, these versions have precision rates of +4/-2 seconds a day.

A 17-day trial

The 9S mechanical movement is assessed against a unique and rigorous set of standards over the course of 17 days. The movement is tested under various conditions including six different positions and three different temperatures, and its daily variations must fit within very strict tolerance rates in order to merit the status of Grand Seiko.


Pursuing an ideal, since 1960.

From the very start, a precise perspective on time.

On December 18, 1960, the first Grand Seiko watch was unveiled. It expressed Grand Seiko’s commitment to the ultimate in precision, beauty and durability, ideals that still define Grand Seiko today.