A method of manufacturing a polymer-insulated conductor. The method includes the steps of a) providing a conductor having a first cross-sectional shape, b) passing the conductor through a conductor-shaping die to shape the conductor such that the conductor obtains a second cross-sectional shape, wherein frictional heat is developed in the conductor, thereby setting the conductor in a heated state, c) applying molten polymer to the conductor when the conductor is in the heated state to obtain a polymer-coated conductor, and d) shaping the polymer-coated conductor by means of a polymer-shaping die to thereby obtain the polymer-insulated conductor.