Watchmaking: A. Lange & Söhne finishing techniques
August 3, 2011
Black polish - the most sophisticated and challenging finishing technique - is performed exclusively on the tourbillon bridge and cage. It can take up to five days to polish one single part.
The Glashütte ribbing emulates a gently rippled effect. The pattern decorates the three-quarter plate and some other large parts of the framework.
Chamfering: At Lange every single bevel on almost all parts is polished by hand, at an angle of exactly 45 degrees. Sharp inner corners are particularly challenging.
The mirror-smooth surface of the flat polish is achieved by rubbing the part in a figure-eight motion on special foils coated with diamond dust.
Contour grinding: The contours of all framework components are given a matt finish to create a vivid interplay with the polished edges.
Circular graining is used on round shapes such as wheels. Unlike most other finishes, this one is applied by rotating the part around the tool.
The perlage consists of small, overlapping circles, achieved with a rotating grinding tip. In A. Lange & Söhne watches, it is mainly used for bridges and plates.
Linear finish: The fine lines in a parallel direction are achieved by sliding a part in one direction over a piece of abrasive paper.
The engraving turns each A. Lange & Söhne timepiece into a unique and personal belonging: Every balance cock is hand engraved with lavish floral elements by one of six master engravers.
The sunray finish is mainly used on bigger wheels and parts of the framework. The graining results in a spirally pattern.
Source: A. Lange & Söhne