Magnetic permeability is the measure of the ability of a material to support the formation of a magnetic field within itself. In other words, it is the ability of a product to be magnetic. It is measured in a unit called μ (Greek letter lower case Mu). It is found in more conductive materials. The more conductive the material is, the higher its permeability. At Suncor Stainless, we use a tool called a Lo MU Permeability Indicator made by Severn Engineering to test magnetic permeability. This test is considered non-destructive testing of a materials stainless steel. Results are also used on material and product certificates when a customer requests them, or they can be part of our own internal inspection process. A typical application for this test is shackles and fittings used in a mine sweeping application.