The invention relates to an axle pin inspection apparatus consisting of: (i) at least one ultrasound probe (SU) for analysing selected portions of a wall (PA) (having known variable outside and inside radius profiles) of a tubular axle pin (AE) in a selected angular sector and, thereby, acquiring analysis data; (ii) inspection means (MC) for determining at least a first and at least a second selected location at which each probe (SU) is to be positioned manually on the outer surface (SE) or inner surface (SI) of the wall (PA), as a function of the profiles and optionally the loading and environment of the pin, so that the probe analyses at least a first and at least a second selected portion of the wall (PA) respectively in at least a first and at least a second selected angular sector oriented along first and second opposing longitudinal or transverse directions and so that the probe acquires analysis data for different relative angular positions of the pin in relation to the probe; and (iii) processing means (MT) for producing charts on the basis of said analysis data, which charts represent the transverse or longitudinal orientations and the echo indication positions inside the wall (PA).