Magnetic Particle Inspection is based on the principle of generating a magnetic field within a test piece. This inspection method is used to detect surface defects in all ferromagnetic materials. For this reason, the test piece to be controlled should be made of strongly magnetized materials.

To summarize the Magnetic Particle Inspection process;

In a magnetized rod, lines of force pass through the rod,
Lines of force are interrupted by the crack causing flux leakage,
Magnetic poles are formed on the crack,
Iron powders are attracted by flux leakage at magnetic poles that occur in the crack.