ASSEMBLY
Numerous crafts are required to manufacture all the components of a watch. Once these components are manufactured and decorated, it falls upon the watchmaker to assemble them, adjust them, and ensure the proper functioning of the watch. Watch assembly is divided into many stages depending on its complexity. Four main assembly stages are defined for efficiency and logistical reasons:
T0: Pre-assembly of components (e.g., setting jewels and pivot holes in a mainplate).
T1: Assembly of the movement.
T2: Fitting the dial, hands, and casing.
T3: Waterproof checks and fitting the strap/bracelet.
Depending on the manufacturer’s criteria and requirements, a varying number of quality checks (functionality, adjustment, aesthetics, etc.) are carried out during the assembly stages.
PRE-ASSEMBLY OF COMPONENTS (T0)
Before proceeding with the movement assembly, certain groups of components need to be pre-assembled. For example, the pins and jewels will be installed in the mainplate and bridges. In the case of small series or industrial production, this operation is often sequenced and entrusted to specialized operators.
MOVEMENT ASSEMBLY (T1)
Once all the components of a movement are checked, they are grouped into kits and handed over to the watchmaker responsible for assembling the movement. The assembly sequence of a movement generally corresponds to the order of its kinematic chain (barrel, gear train, escapement, regulating organ, etc.). Depending on its complexity, assembling a movement can take up to several weeks.
MOVEMENT LUBRICATION (T1)
In watchmaking, proper lubrication is crucial. In the best-case scenario, inadequate lubrication will lead to premature ageing of components and will require more frequent maintenance. In the worst-case scenario, the watch (even when new) simply won’t function. Therefore, the watchmaker must apply the correct lubricant to every friction point (functions, bearings, etc.).
DIAL FITTING (T2)
Once the movement is assembled and regulated, and initial chronometric measurements are taken, it is time to fit the dial(s). Although this step may seem simple, it is important and can be delicate. A thin stone dial can break under the slightest pressure. It is paramount to keep the mounting area clean until the movement is completely cased. That is why these and subsequent steps are often carried out in cleanroom workshops. Humidity and temperature are controlled, the air is filtered, and the workshop is maintained at a slight positive pressure to expel any dust or unwanted particles.
HANDS FITTING (T2)
The fitting of the hands directly follows that of the dial. This operation requires precision and cleanness. The hands must be properly indexed (e.g., at midnight, the hour and minute hands must perfectly overlap and point precisely to their indices). Since there is limited space between the surface of the dial and the bottom of the crystal, the hands must share the height accurately and evenly (e.g., in a split-second chronograph, a minimum of four hands share the central axis and pass over the off-center hands of various subdials).
CASING (T2)
Casing is the stage during which the watchmaker integrates the movement-dial-hands assembly into the case and closes it. Extreme cleanliness and low humidity levels are essential for the success of this process. Generally, the movement is fixed (screwed) inside the caseband. However, there exist various alternative methods for securing the movement to the case.
WATERTPROOF CONTROL (T3)
Every surface connecting two components of the casing (crystals, case, caseback, bezels, crown, pushers, etc.) must be watertight. Various types of seals and adhesives can fulfill this role. Their correct selection and application are essential for ensuring good water resistance.
BRACELET FITTING (T3)
While not the most technical step in the assembly process, this stage seals the manufacturing operations of a watch and gives it its final identity.
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