05/18/2026
Two methods. One surface and near-surface question.
Fluorescent penetrant inspection and magnetic particle testing both find surface-opening discontinuities in metallic components -- but they are not interchangeable.
FPI: works on any material -- ferromagnetic, non-ferromagnetic, aluminum, titanium, nickel alloy. Penetrant enters cracks by capillary action and fluoresces under UV light. Chemistry, process control, and dwell time are the program.
MT: ferromagnetic materials only. The magnetic field causes leakage flux at discontinuities, attracting magnetic particles to produce a visible indication. Faster than FPI on ferromagnetic parts and more sensitive to subsurface discontinuities.
For aerospace structures: MT on steel weld joints, landing gear fittings, engine mounts. FPI on titanium airframe structure, nickel superalloy turbine components, aluminum castings.
Baron NDT performs FPI and MT at Jacksonville, FL and Port Arthur, TX. Nadcap accreditation for PT and MT. ASNT Level III oversight.
baronndt.com