A magnetic inspection device for nondestructively inspecting elongated objects, such as wire cables, pipes, and the like, for loss of metallic cross-section due to abrasion, corrosion, and external and internal discontinuities, having a magnet for inducing in sections of the object between the stations, magnetic flux at the saturation level. A magnetic flux detector having magnetic sensors positioned between the poles and laterally of the elongated object utilizes shields and flux decompressors to render the flux detector more sensitive to leakage flux caused by discontinuities in the objects.