Push‐out experiments on sapphire fibers in both glass and γ‐TiAl matrices show a sinusoidal modulation in the load–displacement trace that is identical in wavelength to the surface roughness of the sapphire fibers. A model, presented in a previous paper, is used to describe the push‐out behavior, and is shown to agree with experiment. The results quantitatively validate the key role of fiber surface roughness during fiber