An apparatus and method for detecting magnetic flux leakage in an object. The apparatus includes a frame assembly, a sensor bar and a U shaped magnetic circuit consisting of first and second magnet and steel pieces 44, 46 and 42 connecting the magnets. The sensor bar is connected to the frame assembly and includes a plurality of coils and at least one sensor operatively connected to at least one of the plurality of coils. The first magnet and the second magnets are connected steel pieces and to the frame assembly. They form a U shaped magnetic circuit which is completed by the steel plate being inspected. The sensor bar is placed between the tips of the U shaped magnetic circuit.