Magnetic Particle Inspection

Magnetic Particle Inspection (MPI) is a non-destructive test method used in various sectors for the detection of surface and near-surface discontinuities in ferrous materials.

Tailwind’s laboratories have bench testing facilities for fluorescent magnetic particle inspection under ultraviolet light.

Commonly bench-tested components include aircraft landing gear, locomotive parts, bolts, nuts, springs, torque tubes, brackets and various crank/cam shafts.

On-site, our technicians routinely employ colour-contrast magnetic particle inspection using permanent and AC yokes to test welds, joints, bolt holes and all other areas of ferrous materials that are prone to cracking or surface-breaking defects.

Magnetic Particle Inspection


  • Large surface areas of complex parts can be inspected rapidly.
  • Surface and subsurface flaws can be detected.
  • Surface preparation is less critical than it is in penetrant inspection.
  • Magnetic particle indications are produced directly on the surface of the part where the flaw is located.


  • Only ferromagnetic materials can be inspected.
  • Alignment of the magnetic field and defect is critical.
  • Large currents may be needed for very large parts.
  • Surfaces should be relatively smooth.
  • Parts must be demagnetized and cleaned after inspection.