Stepped domed acrylic crystal

What is a stepped domed crystal?

A stepped domed crystal is recognisable by the small step cut around its edge: the central section is domed, while the rim forms a lower shoulder. This step rests in the bezel. The profile is often found on old and vintage watches, and the material used here, acrylic (Plexiglas or hesalite), was widely used on these models as well as on pocket watches. It is generally suitable when the original crystal already had this step.

Acrylic: a flexible, repairable material

Why acrylic rather than mineral crystal on these watches? Because it is lightweight and does not shatter into sharp fragments. Its hardness is low: it scratches easily, which is its main drawback. But a scratched surface can regain its clarity through polishing; everything is explained in the guide to polishing an acrylic crystal.

Measuring and fitting

Measuring with a calliper

Measure the old crystal with a calliper, taking the diameter at the base, on the outer edge of the step, not on the domed section. This is the dimension that matches the bezel seat.

Slight oversizing

Generally, an acrylic crystal is chosen slightly larger than its seat: it is compressed when fitted, then expands and stays tight in the bezel. The exact value depends on the case. To avoid mistakes, follow the measuring guide.

Sizes available

See the table below to find the diameter of your stepped domed crystal.

Available diameters