The micro-roughness of a surface is made up of a whole of roughnesses differentiable by their wavelengths respectively by the distance between crests.

The undulation

The undulation has an influence on the level of the aspect of surfaces and plays a great role in the problems of bearing pressure. 

Primary micro-roughness

Primary micro-roughness influences the surface resistance at the time of the first contact and the micro-bearing pressure. 

Secondary micro-roughness

Secondary micro-roughness influences the optical reflection of surfaces and the chemical reactions of surface. 

The control of these various levels of roughness, when it is intended to give to surface particular characteristics, leads to the concept of function of surface. The concept of function of surface is a concept relatively new.

To be able to apply it, it was necessary to have a system of machining able to modify or remove, in a selective way, one of the three great levels of roughness composing a real surface.

The MicroMachiningProcess was invented to meet this need.