T.O. 33B-1-1
Glossary 53
called the north pole of the magnet, and the other which is attracted by the earth’s South Pole and is called the south
pole of the magnet. Magnetic leakage occurs at poles.
MAGNETICALLY HARD ALLOY: A ferromagnetic alloy capable of being magnetized permanently because of its
ability to retain induced magnetization and magnetic poles after removal of externally applied fields; an alloy with high
coercive force. The name is based on the fact that the quality of the early permanent magnets was related to their
hardness.
MAGNETICALLY SOFT ALLOY: A ferromagnetic alloy that becomes magnetized readily upon application of a field
and that returns to practically a nonmagnetic condition when the field is removed; an alloy with the properties of high
magnetic permeability, low coercive force and low magnetic hysteresis loss.
MAGNETIC RUBBER INSPECTION (MT): An inspection process involving the use of a formulation of magnetic
particles dispersed in a room temperature curing rubber. An extension of the magnetic particle method used for
detection of flaws in problem areas such as bolt holes, tubes, etc.
MAGNETIC SATURATION (MT): The degree of magnetization when increasing the magnetizing force upon a part
no longer increases the magnetic flux density (permeability) in the part.
MAGNETIC WRITING (MT): A form of nonrelevant indications, sometimes caused when the surface of a magnetized
part comes into contact with another piece of ferromagnetic material.
MAGNETISM (MT): The ability of matter to attract other matter to itself and exhibit polarity.
MAGNETIZING CURRENT (MT). The flow of either alternating, rectified AC or direct current used to induce
magnetism into the part.
MAGNETIZING FORCE: For the purpose of this discussion, magnetizing force is considered to be the total force
tending to set up a magnetic flux in a magnetic circuit. It is usually designated by the letter “H” and the unit is the
“Oersted.”
MAGNETOGRAPH: A magnetograph is a picture of a magnetic field made by the use of iron powder under conditions
that allow it to arrange itself into the pattern of the field.
MAGNETROSTRICTIVE (MT): The property of changing dimension with changing magnetic field.
MAIN BANG (UT): See INITIAL PULSE.
MAINTENANCE INSPECTION: Inspecting any tooling, machines, or equipment periodically, or during rebuilding to
prevent future in-service failure.
MALLEABILITY: That property which allows a material to be permanently deformed, by compression, without
rupture.
MALLEABLE CAST IRON: A cast iron made by a prolonged anneal of white cast iron in which decarburization or
graphitization, or both, take place to eliminate some or all of the cementite. The graphite is in the form of temper
carbon.
MANIPULATOR (UT): A device used for orientation of the transducer assembly. As generally applied to immersion
techniques provides either angular or normal sound wave path.
MAP: Locating the boundaries of a discontinuity.
