How To Judge The Finish Of A Watch Movement

The “Finish” Of Watch Movements

Forum: TimeZone – Advanced Forum

Date: Sun, 21 Dec 1997 08:44:08 GMT

From: Walt Odets

The following is a reply to Val Joux’s question in the regular Forum.

Of the four items Val Joux lists, only one is really a measure of movement finish, the “polishing of parts.” Blued steel screws, engraving on the rotor, and “gold” (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 gilts 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 overlapping circles). The bridges on the best movements have extremely smooth surfaces, bevelled 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 ashort 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 ofthe 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 jewels, 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 (“chasing”) of bridge surfaces entails a great deal of handwork and, to some, 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, judgement 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, and JLC (in approximately that order, I would say) are the only firms consistently adhering to the highest standards of aesthetic finish. (Others are taking more “pragmatic” approaches to finishing, but may be producing functionally excellent movements. IWC is an interesting example because in using JLC movements, IWC finishes them to a much lower standard.

Visually compare a gold Geographique with a “small” Portugese. Both have a 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 manufacturers are now willing to reveal under a sapphire back. Once you have looked at beautiful movements, many of these will look downright ugly.

Some responses for Justin, Peter, and SJX…

Forum: TimeZone – Advanced Forum

Re: The “finish” of watch movements (for Val Joux)…(Walt Odets)

Date: Sat, 03 Jan 1998 21:39:16 GMT

From: Walt Odets

My post on movement finishing was in response to Val Joux’s question about movement finish – not concept, engineering, or function. Not even about case finish, which is also a whole different issue. The issue of finish, per se, is largely about CRAFT. I have a couple of Oris watches which run as well as the Pateks and I think it’s fair to say that the Oris movements are virtually unfinished – or, finished in a very minimal manner appropriate to their prices. If one were to take a strictly functional approach to watches, mechanical watches would make no sense at all. So, craft is about aesthetic, skill, taste, and technique. A beautifully dove-tailed joint on a cabinet is not the only way to make a durable joint, though it may be the most beautiful way.

There are some qualifications to this idea of “pure” craft, however, because the line between finish and function is soft and complicated. The first qualification on a strict distinction between the two is that no one in their right mind would take a mechanically poor movement and spend a lot of finishing time on it, so level of finish usually has some broad relationship to the mechanical quality of the movement. You could spend weeks finishing a cheap movement (apparently Franck Muller does), but this recalls the Toyota with a $15,000 paint job. A great paint job and a great Toyota, but probably not a great car. The Toyota is simply a certain kind of car – probably the best from a purely sensible, functional point of view – regardless of what you do with the details.

The second qualification is that some finishing clearly has a relationship to function: the finishing of any moving part, especially the wheels, pinions, pivots, and jewels. Finishing is what reduces friction on these parts. Cheap jewels have internal flaws which may fall on a bearing surface. Finally, really crude finishing of even bridges or case backs risks debris in the movement, which would obvioulsy affect function. Poor finish makes the watch harder to service without damaging it and it also reduces the incentive of the mechanic who might, otherwise, use his skills. The feel of a watch at the crown is definitely changed by high levels of finishing in the stem, winding and hand setting trains. Part of the reason for perlage (or other finishes) inside a case back and bridge finishing is to snag dust particles and prevent their floating into the movement. And plating is what protects the steel parts from corrosion. Rhodium is unequalled for this job, and poor plating risks corrosion and thus functional impairment.

As for the Patek-Lange debate, I rate the Patek higher as a matter of taste. The three-quarter plate movement of the Lange is a cheaper (and, to me, aesthetically less satisfying) way to build a watch (I know, I know, it’s part of their tradition, and the chatons and bushings overcome the mechanical objections to a three-quarter plate). So, I include this aesthetic issue under “finishing.” Full bridge movements reveal more of the movement, make servicing easier (only one bridge and wheel need be removed to access a given part of the train), and add a whole aesthetic issue (bridge shape and placement) which is entirely lacking in the Lange. Full bridge movements also demand a lot more finishing, simply because there are more edges to finish. The fine detailing and obvious mechanical quality not withstanding, I find the Lange movements homely (and the chasing on the balance bridges an anachronistic pretense). I placed Audemars where I did, because they are masters of impeccable finish (including their cases, which are Patek’s weakest spot). I might also have included Breguet, which I simply didn’t think of. And Vacheron, at least in the past, has certainly been in the Audemars class. I rated JLC last of the four I mentioned because they tend to have a slightly (SLIGHTLY) more utilitarian approach to finish – maybe knocking off the last 2 or 3 percent Patek might put into finish. Because this is an area of craft, the issue among these really good companies is -again- not about which is the best, but about what a particular person likes. For example, I prefer the COLOR of a Patek or Audemars movement to that of a Lange. That’s aesthetics and taste.