Magnetic Particle is suitable for detection of defects in steel, cast iron and any other ferrous materials where the defect is open to the surface of the item. The material is magnetised, causing an effect similar to the north and south poles of a magnet, at areas where cracks, welding defects or casting defects are located. Magnetic particles (either dry or wet), similar to iron filings, are then applied to the area to be inspected. This, combined with a white lacquer as a highlighting contrast agent, is very effective in defect detection. For applications requiring greater amounts of sensitivity than a visible magnetic particle inspection, the use of a fluorescent light and fluorescent particles can be used. This technique is usually employed on gears, drives and other gearing applications.