Case diameter

31 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 196 references with a sourced case diameter of 31.0 to 31.99 mm, spread across 18 brands and 34 families. Sourced case diameters run from 31 mm to 31.9 mm. By movement type: 23 quartz, 8 automatic, 8 solar, and 2 manual. The most common sourced case material is stainless steel (101 of 153).