HAMILTON FIELD GUIDE

987 & 979 Movements

The evolution of Hamilton's 6/0 series movements reflects significant advancements between 1915 and 1948. It began with the 986 in 1915, followed by the 17-jewel 987 in 1926, and the 19-jewel 979 in 1928. The latter was primarily used in solid gold models. Early 987 and 979 movements featured a metal setting to hold jewels called a jewel chaton that was held in place with screws. In the late 1920s, Hamilton introduced the 987F and 979F; the “F” indicating friction-set jewels replaced the screw-held settings that had their setting simply pressed into the plate.

In 1935, Hamilton launched the 987E, incorporating the Elinvar hairspring and a monometallic balance, marking an advancement in movement reliability and performance. The “E” signified the Elinvar upgrade that addressed issues related to temperature variations affecting timekeeping. By 1937, the 987A was released. It was a substantial improvement over previous versions and only shared some parts with the models that came before it. These advancements and continued improvements showcase Hamilton's commitment to precision and innovation, setting a new standard for reliability in watchmaking during that era.

The following table is provided to clarify the order and year each model was released as it can be a point of confusion for new collectors.