shows an illustration of the process of magnetic particle inspection. A
ferromagnetic part (such as iron, steel, or a magnetic type of stainless steel) is flooded with a
bath of magnetic “fines” in suspension. The part is then magnetized, which causes lines of
magnetic flux to form in the part. Such lines are schematically shown as “flowing” from a north
to a south pole, although the flow is really more of a magnetic direction indicator. These flux
lines will generally stay contained within the part, although certain features of the part may cause
them to leak out into the surrounding air. Geometric features such as tight fillets can cause this,
as well as cracks