MT Magnetic-particle testing

Magnetic-particle testing is used to find surface defects in ferro-magnetic materials (usually steel) and offers the highest sensitivity for evidence of surface cracks.

With the help of different magnetisation techniques, a magnetic field is introduced into the test object. Close to and on the surface of the test object, where the magnetic properties (relative permeability) of the material clearly change (e.g. cracks), the magnetic field appears as magnetic leakage flux out of the surface. This magnetic leakage flux can be visualised with coloured (usually black or fluorescent) magnetisable particles (magnetic powder), which are applied to the test object during the test.

Compared to other non-destructive test methods, magnetic-particle testing can be used with more complicated material geometries and unfinished surfaces.


From its inception, Klaus Gross GmbH & Co. KG has been in the business of non-destructive material testing, which allows us to look back over a treasure-trove of 30 years of experience. This experience, combined with a high degree of flexibility and highly motivated staff, has characterised us from the beginning.

We can carry out any process we offer either at our premises or at the client's location. This applies to HT, PT, MT, RT, UT or VT tests; on request, we can provide a complete evaluation and documentation directly on the spot. We can ensure this as we use only personnel qualified at Level 2 in our operation. For test supervision, there is also a Level 3 tester in house.

For many years, our range of activities has included the inspection of drilling rods. In this respect, we have trained some of our employees in the NS2™ standard, which ensures the highest level of quality.
See the sub-menu points for a quick overview of the testing processes we carry out. Our skilled personnel are available for questions at any time.