Abstract: The induction hardening machines are utilized in
the industries which modify machine parts and tools needed to
achieve high ware resistance. This paper describes the model of
induction heating process design of inverter circuit and the results
of induction surface hardening of heating coil. In the design of
heating coil, the shape and the turn numbers of the coil are very
important design factors because they decide the overall operating
performance of induction heater including resonant frequency, Q
factor, efficiency and power factor. The performance will be tested
by experiments in some cases high frequency induction hardening
machine.