PIPE

In watchmaking, the Pipe generally refers to any part or portion of a part that is cylindrical and hollow, i.e. tubular. The most common example is the Hour wheel, commonly called the pipe wheel: its hub extends into a tube onto which the Hand hour hand is fitted, and inside which passes the shaft carrying the minute hand, thus achieving the coaxiality of the displays. There are also Pipes used as a bearing surface, spacer, or guide for other components. The Pipe often serves a dual function: keeping an element at the correct height and allowing an Axis to rotate or slide at its center. Its manufacture requires precise Reaming of the inner diameter and a good surface finish, as this determines the Set and friction of the parts it receives. Though a modest element, the Pipe contributes to the compact, coaxial arrangement characteristic of watch movements.