... , aluminum, chromium, copper, rubber, paint etc.) on magnetic metal matrix iron (such as: iron, steel, alloys and hard-magnetic steel ... on copper ,aluminum, stainless steel and some non-ferromagnetic matrix AT-23(Plastic probe separated type magnetic)AT-260(wholeness ... of copper ,aluminum, stainless steel and some the non-ferromagnetic matrix, such as paint, powder, all kinds of anticorrosive coatings, ...