The chamfer is a concave angle that can be found around the holes of a movement. The chamfers are generally found on the bridges and mainplates around the rubies and screws. A chamfer around a ruby is also called a sink.

Chamfers have been made consistently throughout the history of watchmaking. We have about as many today as we did in previous centuries.

The artisanal method lends itself very well to chamfers. They can be made to measure. In the highest quality, watchmakers will go so far as to set the stones in place once before removing them for flush-cutting. This allows the light to reach the rubies and screws as well as possible, which enhances their appearances. For the artisanal method, watchmakers will almost always make mirror-polished chamfers, which will further enhance the reflection.

For the semi-artisanal method, the chamfers will often be made in series and will not always be adjusted to the final position of the stone or screw. That said, they will generally be mirror polished and a nice reflection will be present.

For the industrial method, the chamfers are made in series and sometimes remain matt. This means that the brilliance of a stone or screw will be better than if there were no chamfers, but the reflection will not be as good as with more traditional production methods.