This International Standard specifies a method for calculation of the lower and upper limits for the average outer diameter of cables and the outer dimensions of flat cords with circular copper conductors and of rated voltages up to and including 450/750 V. This standard is not applicable to mineral insulated cables. The method shall not be used to calculate the diameter over the core assembly for determining the sheath thickness; the method given in Appendix A of IEC 502 shall be used for this purpose. NOTES 1 It is stressed that the conductor diameters given in the tables are intended only for use in this standard as a basis for calculation and are not intended for verification by measurement. 2 The factors given in 2.5 and 3.1 of this standard may be varied in preparing standards for cables in which the number of cores, the hardness of the insulation, precise positioning of the conductors or other factors may affect the dimensional tolerances permissible.