Electrical technique for forming needle point - by electrical heating before drawing wire to form neck

摘要

In order to form a sharp point, a length of metal wire is held between two electrodes, and an electric current passed along it. The electric current is of such a strength that the metal becomes plastics, and the electrodes may be moved apart, stretching the wire. - The neck is then drawn into a neck which separates to leave two points. By varying the heating current, points of different shape may be formed.(0/4)