The effect of uniaxial mechanical stress on the magnetic properties of electroplated Ni films was measured with a magneto‐optical Kerr loop tracer. We show that the effect of stress on the coercive force is completely different for thin (20 nm) and thick (10 &mgr;m) films. The latter behaves like bulk Ni, whereas results on lower thicknesses show a continuous transition from thin film to bulklike behavior. The results are discussed by assuming different micromagnetic reversal processes for the two extremes: rotational for thin film and domain wall movement for bulk. ©1996 American Institute of Physics.