Case diameter

20 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 237 references with a sourced case diameter of 20.0 to 20.99 mm, spread across 15 brands and 44 families. Sourced case diameters run from 20 mm to 20.8 mm. By movement type: 152 quartz, 28 automatic, 5 solar, and 4 manual. The most common sourced case material is stainless steel (27 of 31).