Magnetic-particle testing relies on the action of magnetic flux forces on ferromagnetic particles applied to the surface of the tested object. If a flaw occurs, the magnetic flux is dissipated and the distribution of the particles in the area of the flaw changes. The concentration of magnetic particles generated over the flaw is known as a magnetic-particle indication.

These tests are conducted with the use of PARKER B300S yoke and detecting agents (the magnetic powder, cleaner, primer) from MR-Chemie GmbH.