A work‐hardening model for ordered and disordered single‐crystalline alloys, where only one slip system is operative, is presented. The model is based on the experimental observation that most of the dislocations on parallel slip planes are locked as dipoles and this dipole formation is believed to be the principal source of work hardening. A detailed analysis of the behavior of passing dislocations is made as a function of frictional stress and vertical separation. Qualitative arguments for the observed strengthening in ordered and disordered alloys are presented based on the above analysis. The pronounced work hardening observed in ordered alloys is related to increased dipole strength as well as to reduced cross slip occasioned by atomic ordering.