Case diameter

21 mm watches

On the small side by modern standards; sizes like this were the norm for mid-century watches. Lug-to-lug length and case thickness matter as much as diameter for how a watch fits.

Watchfari lists 82 references with a sourced case diameter of 21.0 to 21.99 mm, spread across 14 brands and 24 families. Sourced case diameters run from 21 mm to 21.9 mm. By movement type: 51 quartz, 3 manual, and 2 solar. The most common sourced case material is stainless steel (26 of 41).