Assembly screw (1) for the pivoting attachment of at least two horology components in a position of assembly, the assembly screw (1) comprising at least one guide portion (3) allowing one of the horology components to pivot, and at least one threaded portion (4) allowing it to be fixed to another horology component, wherein this screw comprises a shoulder (5) intended to come into abutment against this other horology component and a zone (10) of lower mechanical rigidity to reduce the contact pressure applied at the shoulder (5) of the assembly screw when the horology components are in the position of assembly.