Deals with magnetic particle testing of both seamless and welded ferrous pipes having an outside diameter of not less than 1/8 inch (3.2 mm). It does not apply to the testing of pipes of non-ferromagnetic materials e.g., austenitic stainless steel. This part is primarily applicable to magnetic particle examination for the detection of imperfections which are at or near the exterior surface of the pipe. The method covered by this part is that in which a magnetic flux is induced in the pipe or tube. Where an imperfection is present which distorts the flux pattern, it is detected by the aggregation of applied magnetic particles.