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Magnetic Particle Inspection

We offer both on-site and in-house MPI testing service. Our dedicated UKAS accredited MPI laboratory and highly skilled on-site technicians offer a service unrivalled within the NDT industry.


Our MPI testing service is utilized by a wide range of clients from all sectors of industry from motorsport and classic car restoration to the film industry, military applications, general engineering and many more.

Our UKAS accredited in-house and site service facilities is a vital form of NDT for many of our customers around the UK and Europe.

Significant investment in our all new facilities in Stokenchurch enables NFW Inspection Co Ltd to offer level of testing excellence that are the envy of other service providers.


Magnetic particle Inspection (MPI) is a non-destructive testing (NDT) process for detecting surface and slightly subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys. The process puts a magnetic field into the part. The piece can be magnetized by direct or indirect magnetization. Direct magnetization occurs when the electric current is passed through the test object and a magnetic field is formed in the material. Indirect agnetization occurs when no electric current is passed through the test object, but a magnetic field is applied from an outside source. The magnetic lines of force are perpendicular to the direction of the electric current which may be either alternating current (AC) or some form of direct current (DC) (rectified AC).