Perlage or perlée
"Watch components that are given a perlée pattern may include the movement main plate and bridges, the inside of the watch case and the watch-case bottom. The perlée patterned parts of a wrist watch are commonly invisible from the outside except if the watch has a transparent casing or deliberately exposed internal parts.
Further grinding patterns used by watchmakers include the clavus pattern, also known by the French term oeil-de-perdrix (partridge eye)."