AXIS

In horology, the term axis refers both to the theoretical line around which a part rotates and to the physical part that materializes this rotation. An axis is generally a rod ofSteel hardened, whose thinned ends, the pivots, rotate in jewels or bearings. The best-known example is theBalance staff: this is the part onto which the Balance and the roller table are pressed, and whose pivots ensure the Oscillation of the regulating organ. We also speak of the Barrel axis, the wheel axis, or the hand hands axis. The quality of an axis relies on the precision of its pivots, their Polished and their alignment: the slightest defect causes friction, premature wear or variations in rate. Particularly fragile, the Balance staff is protected against shocks by shock absorbers. The Axis illustrates the central role of the pivot-jewel pair in horological mechanics.