Magnetic testing is a non-destructive testing process for detecting surface and subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt and some of their alloys.

A magnetic field is induced in the part under examination. Discontinuities in the material allow the magnetic flux to leak. Ferrous iron particles are then applied to the part, either dry or in a wet suspension, for visualisation and detection (build up at the area of leakage).

Application fields: cast parts, forged parts, welded parts, demagnetisation (before welding), etc.