Abstract: A process for heat treating steel wires in which the wires are passed through an induction furnace with induction coils connected in series to a common power supply. No more than one wire passes through any one of the induction coils. The wires are heated to their Curie temperature, where the wires become non-magnetic. This makes the process substantially self-regulating. If one or more wires are heated more rapidly than others, little if any heating of the more rapidly heated wires will occur after they reach their Curie temperature, and all wires will leave the inductive heating furnace at or near their Curie temperature. The system will operate satisfactorily with one or more wires missing. When this happens, for loading purposes or other reasons, the efficiency of the unit degrades but sufficient excess power remains such that heating of the wires that are passing through the system will be relatively unaffected at the design mass flow rate.