The sorting conditions for the construction materials that have been studied so far refer more to ideal ones. Complex mathematical relations have been worked out for these cases. But, factors that appear in the real operating conditions of the vibrating equipment, that have not been quantified so far, have a huge influence on sieving materials with critical humidity, materials having the humidity between 5 and 15% -critical humidity- on meshes between 5 and 10mm, and rapidly can damaged the screening equipment. This book is an attempt to define and systematize the factors that influence the screening of materials, find the actual values for the main parameters, and a specific domain of vibrations for such materials. Also, the work deals with additional factors of influence and the effects of their action that results from the effective operation and some experiments. Useful norms and parametric graphs have been drawn up for concrete cases of designing vibrating screening equipment. The work should be useful to professionals that are working with such equipment, industrial designers, and students, in order to realize the complexity of the real operating phenomenon.