Tolerances

Problems periodically arise concerning magnetic and mechanical tolerances of ferrites. The nominal and spread of a sample lot is not always indicative of production lots. As an example, toroids are supplied to a nominal AL value based on material grade, and a tolerance of +/- 20%. The nominal AL value for a large number of production lots is considered to be at 0.0%, then the total spread of a large number of shipments will be +/- 20% around this nominal.

Sample parts with given characteristics positioned at some desired point within the normal spread cannot be easily produced because chemical processes cannot be controlled this closely. For this reason, it is difficult to fill requests for "maximum" and "minimum" samples. Every Ferrite International sample is supplied with data showing our measured values on each sample compared to the specification upper and lower limits