Working with a transmission gear manufacturer, TOCCO, Boaz, Ala., launched a single frequency gear heat treatment process. The system is based on the use of a precisely selected, single programmed frequency to produce the required diametrical pitch gear tooth profile hardened pattern. The system has the ability to provide the optimum balance of root versus tooth tip heating. The technique uses an adjusted single frequency applied at high intensity power to suit each particular tooth size and geometry relative to diametrical pitch (module). As a result, it can produce the desired profile pattern with substantiated pitch line depth (preventing both surface and subsurface failure), plus required root-bonding strength.