Abstract: A method of manufacturing a coil for a transformer and in particular a high voltage transformer in which the starting end of a wire with a bondable thermoplastic sheet is electrically conductively connected to an axially slit sleeve of non-magnetic metal which sleeve is placed on a rotary winding tool to form an essentially cylindrical wire winding directly on the sleeve with the end faces of the sleeve extending beyond the winding. Heat is applied to the winding to bond the individual turns to each other. One end of the sleeve carrying the winding is placed on the bottom of a casting mold and the end of the wire remote from the starting end is connected to a terminal. A casting compound is introduced into the mold to anchor the connecting terminal. The outside of the casting compound is provided with an electrically conductive casing which is electrically connected to the sleeve.