4. Industrial surfaces and their practical characterization

4.1 Industrial surfaces

The appearance of an industrial surface depends on all the operations carried out; in particular, it always includes the "imprint" of the shaping tool. Each surface must therefore be properly inspected before being put into service. A scanning electron microscope is often chosen, as its magnification range is very wide (from × 30 to × 30,000 times in some cases). Each industrial sector can thus build up an "atlas" of the main facies, depending on the finishing tool; in the case of a flat surface of a steel product, for example, we might find :

• regular, criss-cross milling scratches ;

• scratches tightened after grinding ;

• fragmented topography, even...