a movement consists of performing all the decorative operations
once the functional machining work has been completed. All the surfaces
of parts are touched up, corrected and decorated by hand.
diagram to the right :
A) The top surface
B) The flank
C) The external angle
D) The interior angle
E) The rounded angle
The hatched lines show the BEVEL or the chamfer
is one of the finishes most representative of high-end watchmaking,
consisting of cutting down and polishing the angles, known as chamfers.
The outline of the shape is thus underscored as the light lays over
the bevels. (hatched lines on the diagram above).
The following tools are used for chamfering the parts : files, buffs,
burnishers, stones and polishing lathe. Bevelling is an extremely
meticulous task enabling the elimination of traces of machining
and unattractive burrs that might also impede the smooth running
of the mechanism.
Rough part * (1) : After machining, and prior to decorations.
Precision-machined parts could in fact, once trimmed, be immediately
fitted in the movement, as they are operational.
Interior angle * (2) : this applies to the place where two
bevels meet on an inside corner. It must look like a single geometrical
line where the two bevels meet.
No machine is capable of creating an interior
It is a very difficult type of finish that calls for expert hands.
Rounded angle * (3) : In this case, the intersection of the
chamfers is rounded. This type of bevel is not as difficult to achieve
as an interior angle.
External angle * (4) : This is an angle formed where two
bevels meet towards the exterior. This angle must be sharp and neither
blunt nor rounded.
Bevelling : its usefulness
cut-down angle is first and foremost a form of trimming which makes
the parts less fragile during handling: moreover, polishing limits
the risk of corrosion. Parts could be roughly trimmed, but the determination
to accomplish a fine piece of workmanship and to create optical
effects leads the craftsman to polish the chamfer. (Photo 5)
- (photo 6) non-decorated prototype of a grande sonnerie minute
- (photo 7) decorated movement of a grande sonnerie, minute repeater,
carillon, power-reserve and dynamograph mechanism
criteria of bevelling : regularity is important. The bevel must
not start off small and end up larger.
The curve of the bevel should be beautiful : the angle is
curved or very slightly rounded It is crucial that the bevelled
edge be clean , even under a magnifying glass.
Twisted bevels are not pleasing. The bevel may be regular
but must not twist like a propeller blade.
Faceted bevels are unacceptable, as they give an unrefined
Dull patches are dark. The quality of polish must be impeccable.
A watch with no decorations, but which has nonetheless been carefully
assembled, works very well* (photo 6), yet the watch appears
lifeless and lacks luminosity: one might say it has no soul. The
absence of a fine finish detracts from the effect of the precision
devoted to the parts in mechanical, horological and assembly terms.
the other hand, (photo no. 7) provides a better idea of just
how meticulous the work of bevelling actually is, requiring tremendous
dexterity. One might nonetheless argue that all these efforts imply
a great deal of time and serve no functional purpose ; nonetheless,
is it not obvious that this all-but forgotten art gives each part
a remarkable aesthetic finish that enhances the appeal and value
of the watch as a whole ?