Studies of cathode spot division have been made for vacuum arcs with solid metal cathodes of zinc, lead, copper, aluminium and bismuth for discharge currents in the range 5-150 A. The distribution function of the number of spots is Gaussian for fixed experimental conditions. Above a certain current i0 the mean number of spots increases linearly with current except for bismuth. A model for spot splitting is proposed which is based on the energy balance at the cathode surface and temperature-field emission for electrons.