Defines the criteria and levels of acceptance for magnetic particle inspection of welded and seamless ferromagnetic steel tubes for detection of surface imperfections. For the detection of surface imperfections on the total, or part of the outer surface of tubes, with the exception of the end bevel/face. May also be used, where appropriate, to locate external surface imperfections which are detected by a different non-destructive test method; such as ultrasonic, prior to dressing of the tube surface, and to ensure complete removal of the imperfection after dressing is complete.