Era · 1920–1939

Interwar pocket watches

Railroad rules settled on a 16-size, open-face, lever-set watch with at least 19 jewels, and new 18-size watches were shut out of service during the 1930s. In 1931 Hamilton introduced the Elinvar hairspring, which kept time steadier through heat and cold and led to the 992E. Wristwatches dominated everyday sales by 1930, and the railroad pocket watch carried on as a working tool.

3 references we cover.