magnetic inspection paste

magnetic inspection paste

[mag′ned·ik in′spek·shən ‚pāst]
(metallurgy)
A paste containing ferromagnetic particles designed to be added to a light distilled petroleum oil, such as kerosine or naphtha, to form an inspection penetrant; when the inspection penetrant is applied to a metal, the ferrous particles accumulate in any surface cracks by magnetic attraction, thereby permitting the cracks to be discerned.