There is provided a method for manufacturing a batch of horological balance springs (2a), the average of whose stiffnesses lies within a predetermined range, and the method includes forming in a wafer the horological balance springs (2b, 2c) with dimensions that differ from the dimensions required to obtain the batch of horological balance springs (2a), the average of whose stiffnesses lies within the predetermined range, determining the stiffnesses of the systems, computing a dimensional correction to be applied to the horological balance springs, and modifying the dimensions of the horological balance springs (2b, 2c) formed, on the basis of a dimensional correction computed to obtain the batch of horological balance springs (2a).