This standard describes three methods of test to determine the bond strength of impregnating agents such as solvent-based varnishes and solventless resins to an enamelled wire substrate. Bond strength may be affected by cure, by test temperature, by thermal ageing, and for any impregnating agent, by the chosen type of wire enamel. These three methods of test cover the prevailing standard practice of testing bond strength. For a certain group of materials, one of these methods may be assigned to be the referee method subject to a specification in the relevant specification sheet.