Chapter 5

Why a micrometer matters

In a mechanical watch, the power retained in the mainspring is transferred via a gear train to the escapement, whose accurate and efficient transmission of this energy to the balance is critical to the overall performance of the watch. This is why, in every current 9S caliber, Micro Electro Mechanical Systems (MEMS) technology is used to manufacture the escape wheel and pallet fork, two of the key parts of the escapement. Thanks to MEMS, these components are manufactured with extreme precision, to tolerances of a micrometer, or 1/1,000th of a millimeter. Furthermore, this technology also makes it possible to skeletonize them and so reduce their weight with the result that the efficiency of the energy transmission is maximized. MEMS’ ability to allow the creation of complex shapes also results in each tooth of the escape wheel having a step at its tip that assists the retention of the lubricating oil and so increases the durability of the whole escapement.

Developed entirely in-house, Grand Seiko’s MEMS technology plays a major role in ensuring that every 9S mechanical watch meets the Grand Seiko Standard and delivers many, many years of precise timekeeping. A micrometer may be tiny, but it matters hugely.