BALANCE SPRING
Component of the regulating organ, determines the movement's precision. The material used is mostly a steel  alloy (e.g. Nivarox), an extremely stable metal compound, In order to prevent the system's center of gravity from continous shifts, hence differences in rate due to the watch's position, some modifications were adopted. These modifications included Breguet's overcoil (closing the terminal part of the spring partly on itself, so as to assure an almost perfect centering) and Philips curve (helping to eliminate the lateral pressure of the balance-staff pivots against their bearings). Today, thanks to the quality of materials, it is possible to assure an excellent precision of movement working even with a flat spring.

BALANCE

The beating heart of a mechanical movement is the balance. Fed by the energy of the main spring, a tirelessly oscillating little wheel, just a few millimeters in diameter and possessing a spiral-shaped balance-spring, sets the rhythm for the escape wheel and pallets with its vibration frequency.

 

BARREL

Component of the movement containing the mainspring, whose toothed rim meshes with the pinion of the first gear of the train. Due to the fact that the whole ----made up of barrel and mainspring----transmits the motive force, it is also considered to be the very motor. Inside the barrel, the mainspring is wound around an arbor turned by winding the crown or, in the case of automatic movements, also by the gear powered by the rotor.

BEARING
Part on which a pivot turns, in watches mostly a jewels.

BEVELING

Chamfering of edges of levers, bridges and other elements of a movement by 45 degrees, a treatment typically found in high-grade movements.

BEZEL
An outer ring surrounding the watch dial.

BLUED SCREW
Traditional Swiss and Glashutte watchmaking dictates that a movement should contain blued screws for aesthetic reasons. Polished steeled screws are heated (or tempered, as it is known in watch parlance) to 290 degrees Celsius. This process relaxes the steel, turning it a deep blue in color. Only a few manufactures still put the tempering process in effect with actual heat, others preferring the chemically induced version that assures an even color every time.

BRACELET

A metal band attached to the case. It is called integral if there is no apparent discontuity between case and bracelet and the profile of attachments is similiar to the first link.

BREGUET HANDS
A particular type of hands in a traditional elegant shape.

BRIDGE
Structural metal element of a movement --- sometimes called cock or bar ---- supporting the wheel train, balance, escapement and barrel. Each bridge is fastened to the plate by means of screws and locked in a specific position by pins. In high-quality movements the sight surface is finished with various types of decoration.

BRUSHED, BRUSHING

Topical finishing giving metals a line finish, a clean and uniform look.