Enameled wire is a main type of magnet wire, which consists of two parts: the conductor and the insulating layer. The bare copper wire is annealed and softened, then painted and baked for many times. The conductor shall be copper wire, oxygen-free and low-oxygen copper wire with smooth surface, roundness, uniform quality and no defects as specified in the specified standard. The copper wire is coated with continuous and smooth synthetic resin without foaming and other impurities. Magnet wire insulating films mainly use (in order of increasing temperature range) polyvinyl formal (Formvar), polyurethane, polyamide, polyester, polyester-polyimide, polyamide-polyimide (or amide-imide), and polyimide, to achieve different technical standard.