This test procedure specifies@ in accordance with the provisions of I EC Publication 216-1@ a method for evaluating the temperature index of round enamelled winding wires. It is not applicable to rectangular winding wires or to fibre-insulated winding wires. In order to avoid undue fragility of the test specimens@ experience has shown that sizes from 0.8 mm to 1.5 mm are generally found convenient to handle and test.