  Traditional tolerancing considers the conformity of a batch when the batch
satisfies the specifications. The characteristic is considered for itself and
not according to its incidence in the assembly. Inertial tolerancing proposes
another alternative of tolerancing in order to guarantee the final assembly
characteristic. The inertia I2 = \sqrt{\delta^2 + \sigma^2} is not toleranced
by a tolerance interval but by a scalar representing the maximum inertia that
the characteristic should not exceed. We detail how to calculate the inertial
tolerances according to two cases, one aims to guarantee an inertia of the
assembly characteristic the other a tolerance interval on the assembly
characteristic by a Cpk capability index, in the particular but common case of
uniform tolerances or more general with non uniform tolerances. An example will
be detailed to show the results of the different tolerancing methods.
