Magnetic particle inspection (MT) is used to detect surface and subsurface discontinuities in ferromagnetic materials. The advantage of the method is high inspection speed, less labor and material costs, compared to PT method, as there is no need for high preparation of the surface for inspection. Disadvantage of the method - difficult implementation in hard-to-reach places, method needs a supply of electricity, it is suitable for ferromagnetic materials only. If permanent magnetic field is used - it might be required to do the demagnetization of the parts.