Following the trend toward upgrading the industrial technology, a variety of transformers, small motors, devices for communication, special windings, and so forth have been recently developed by the electric and electronic manufacturers in Taiwan. Therefore there is a need for improvements in the characteristics of wire to respond to the increasing demands. In such a case, it is obvious that the conventional polyurethane enameled copper wire (UEW) cannot serve satisfactorily due to its inherent limitations. On the basis of this knowledge about UEW and the cumulative experiences of the past, a heat-resistant polyurethane-coated copper wire with a thermal class of 130 (class B) - UEW-B which can be applied to heat-resistant coils - has been developed in our factory.