The bore
In a recorder, the length and shape of the bore (interior profile of the recorder) are the characteristics that determine the height, the pitch, the compass, the fingering as well as the tone. This profile could have varied aspects from a quasi cylindrical shape to a sharply marked reversed conical bore (see drawing beneath.)
During the drilling, the precision requires 1/50th of a millimeter adjustements of the diameter in order to obtain the correct functioning. Reamers are the tools that allow to work with such a precision.
