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The Encyclopedia of Horology

Component record · Case

Dust Ring

Partially verified

A ring fitted between movement and case to exclude dust.

What it does

Closes the gap around the movement inside the case.

How it works

It fills the annular gap so dust entering the case does not reach the movement directly.

Evolution

Materials changed from metal to moulded plastic in later production.

Known variations

  • Metal dust ring
  • Moulded ring

Identification for collectors

  • A missing ring often accompanies a movement fitted to a case it did not leave the factory in.

Common failure modes

  • Loss during service
  • Deformation

Diagram

bezelcrystalback and cuvetteband, bow and pendant
Schematic: case construction. An outline schematic drawn to show the arrangement of the parts discussed here. It is not a dimensioned working drawing and does not depict a particular maker's calibre.

Sources & references

  1. de Carle, D., Practical Watch Repairing
  2. de Carle, D., Watch and Clock Encyclopedia
  3. Daniels, G., Watchmaking

Where sources disagree, the disagreement is stated rather than resolved silently.