Take me home
Of the four techniques most commonly used by contemporary manufacturers to impart an appearance of quality finish to movements, only one is truly a measure of quality of finish, the "polishing" of parts. Blued steel screws, engraving on the automatic winding rotor, and "gold" surfaces (or, more usually gilt) may be aspects of fine movements, but today are more likely to be relatively cheap shortcuts to give movements a distinctive look. Almost everyone who uses the ETA 2892 these days engraves and gilds the rotor, and many also use blued screws. These don't, in themselves, add up to a beautifully finished movement.
Among the criteria to judge the finish of a movement:
1. Bridge surfaces may be roughly smoothed (in very cheap movements), gilt, or (in the best movements) rhodium plated. Before plating, bridges in high quality movements are decorated with various patterns. The best known pattern is the Geneva Bars (or cotes de Geneve) and the less costly perlage (swirls of over lapping circles). The bridges on the best movements have extremely smooth surfaces, beveled edges (anglage), recessed screws with polished surfaces on the recesses (this called "moulding" or oeil de perdrix). The plating should be almost white, not gray or yellow, and without stains or scratches. The spacing between bridges should also be regular.
2. All screws should be polished. In order from good to best, screws will be: flat-polished; polished, chamfered screws (anglage between the polished top surface and burnished sides of the screw); flat-polished, chamfered outer edges, and chamfered slot edges. The heads of the screws should be absolutely level with the bridge surfaces (excluding screws whose function relies on projection above the surface, such as balance regulator screws).
3. All exposed steel parts (click, regulator lever, etc.) are polished, and in the best watches, the polish should be "black," giving a deep, glossy finish. Poorly polished parts are gray in appearance. The quality of the polishing is a product of a complete lack of any marks or unevenness of the surface. The best work also burnishes and rounds the edges of these parts.
4. The finish on the ratchets and wheels is important. In increasing order of quality (more or less), there are voluted ratchets (a spiral pattern or other design running out from the center); voluted ratchets with bevelled toothing (polished, chamfered edge on the toothing); "large gouge volutes" (a star-like pattern of lines radiating out from the center)and stopping a short distance from the outer edge and bevelled toothing; "diamante" finishing (a moire-like surface) and bevelled toothing.
5. The finish of a movement is enhanced by good quality jewels which are well set in the plate or bridge (or attached). Stones of darkest color and clarity are most desirable. (In the synthetic rubies used in almost all watches today, coloring is achieved by adding chromium oxide to the aluminum oxide and the purity of ingredients determines clarity). When the jewel is set directly into the plate or bridge (friction jewelling), it is set into a hollow with sloping sides (the "decouverture"), which must be perfectly burnished in the best movements (this enhances the brilliance of the jewel). Jewels may also be set in "chatons." Instead of setting the jewel in a hole drilled in the plate, the jewel is set in a ring (the chaton, often made of gold) and the chaton is screwed to the plate. The shape of the j ewels, the shape of the holes in the jewels, and the use of jewels in pairs ("cap" jewels or "combined" jewels) are important in determining the quality of the movement, but more a matter of function than finish. Diamond, instead of ruby, may also be used for cap jewels.
6. The "non-visible" parts of the movement (on examination with the movement in the case, with the back removed) are as well finished as the "visible" parts. The bottom of the plate (the surface and motion works under the dial) is especially revealing of movements that are well finished.
7. Engraving of words and numbers on the movement bridges should be even, well-formed, and of even depth. Decorative engraving ("chasing") of bridge surfaces may also be done and entails a great deal of handwork. To some, such chasing enhances the beauty of a movement. I usually find it unattractive and superfluous in an otherwise beautifully finished movement. Chasing often detracts from the perception of the function of a movement.
Really beautiful movements, finished as I have described above, have an immediate and unmistakable appearance on visual inspection. The perfect color, gloss, and sheen, seen even with the naked eye, gives the movement an immaculate, silvery, almost ethereal quality. This kind of appearance is the product of many fine operations. As I have said before, judgment about the quality of finish of a movement (or the quality of its design and construction, which are different issues) can only be learned by looking at movements. The naked eye, a 4 power loupe, and a 10 power loupe will each reveal different aspects of finish and quality, all important to the watchmaker.
One should start by looking at really fine movements to develop a standard. Among all current manufacturers, Patek, Audemars, Lange, JLC, and Breguet stand out as the firms consistently adhering to the highest standards of aesthetic finish. Most others are taking more "pragmatic" approaches and may be producing functionally excellent movements. IWC is an interesting example because in using JLC movements, IWC finishes them to a lower standard. Visually compare a gold Geographique with a Portugese, both with sapphire back.
It should be obvious from this description of finish that blued screws, gilt surfaces, or an engraved rotor do not constitute good finish of a movement. In the current marketing climate (with such heightened awareness about mechanical movements), such cheap efforts at the appearance of quality have become common. It is amazing what some manufacturers are now willing to reveal under an exhibition back.
Take me home
This page was created by Peter Chong. Last updated January 20, 1998.