Making of the Parts of a Watch
How a Wristwatch's Movement, Dial and Case are Created and Shaped
The work of creating by hand the component parts of a watch, especially its movement, is painstaking. Here's a basic look at the process of making watch parts.
The Movement of the Watch
A watch’s movement includes its winding mechanism, mainspring (the part of the watch that coils when wound, creating power), gear train (the grooved wheel-and-pinion system), balance (a circular piece that oscillates on an axis at regular intervals), balance-spring (an elastic piece that keeps the balance moving regularly – together, the balance and the balance-spring are the “organ”) and escapement (a piece that fits between the gear train and the organ to stop the gears and start the balance at intervals). In short, the movement of the watch is anything that is not the face, hands or back.
How the Movements are Made
Watchmaking engineers and micromachinists use delicate digital instruments to create the prototype for each movement, which can be composed of hundreds of tiny parts, some sculpted from metal or shaped with lasers. Each basic form is minutely shaped, grooved and contoured to fit with its attendant parts, sometimes by machine. At each stage of the process, however, everything is hand inspected.
Today’s watches are sometimes “skeletonized,” or crafted with a transparent sapphire crystal case back that shows off the precise craftsmanship. Most movements, however, are never seen. The extraordinary thing about fine watchmaking is that the same level of care and finish is afforded to a boldface movement as is to one that will be hidden for a lifetime.
Preparing and Shaping Watch Movements
Each fragment of the movement is polished, brushed, stippled, satin-finished or, in some cases, engraved. Each screw is flame-fired; each edge is beveled, or chamfered, as it’s known in fine watchmaking. All traces of machine intervention are wiped away during this completely manual process that relies on knowledge of centuries-old techniques and on specific tools.
Sometimes a boxwood pad and a lathe are used to decorate the surfaces of some of the larger parts with a pattern of straight lines or circles; Côtes de Genève is just such a pattern.
The care taken in finishing the parts of a movement is manifold in purpose: aesthetically, the various brushing and chamfering techniques provide different patterns, textures and levels of reflective light; pragmatically, the finish is far less likely to corrode than it would be if left untreated; and abstractly, taking such an extreme degree of care in crafting parts that will never be seen is a reflection of the pride of artisanship, and it contributes to the ongoing sense of freemasonry among the artisans.
According to the Fondation de la Haute Horlogerie, the process also “guarantees technical perfection, for no one would devote hours to polishing, engraving and embellishing an imperfect part.”
Lastly, the watchmaker meticulously connects the various finished parts into a smoothly functional movement.
Making the Watch Dial
A sheet of gold, silver or copper riveted with pins typically forms the base of the watch face, or dial. The watchmaker decorates the face with straight or circular lines cut into the metal, each only several tenths of a millimeter wide, in a very old process called “guillochage.” He then uses a diamond-edged instrument to drill a hole for the “arbours” of the hands, and applies Arabic or Roman numerals, if any, to the face.
What Goes Into a Watchcase
The watchcase includes its back, middle, bezel and crystal covering. The middle is cut from a block, and the back from a sheet, of gold or steel. The parts are heat-treated, soldered together, cleaned with ultrasound, burnished and then polished or satin-finished. After engraving the back and setting a sapphire crystal into the bezel, the case is ready to be fit with the watch’s movement.
