Magnetic Particle Testing is an inspection method with which defects on the surface or close to the surface (to a depth of approx. 2 mm) in a ferro-magnetic material can be traced.
It uses the principle that a discontinuity on the surface causes a magnetic leakage when apply a magnetic field to the object. A crack will be made visible by an interruption of this field.
The indications that are found are judged by their nature, size and location with the aid of an inspection standard. The shape or dimensions of the object do not generally limit it.