Is usually defined as “windproofing” The ability of a window to withstand the stresses determined by violent and sudden changes in pressure, such as those causabili by the wind, reacting in the elastic range and therefore capable of supporting a permissible deformation such as to make them maintain its shape and its initial properties, and of course of safeguard the security of the people. The test method is carried out in the same laboratory equipment used for other types test (air and wind), and provides a series of checks to determine the ability of the casing to withstand sudden stresses: 1. after assignments pressures of adjustment is made to the test to deformations, which detects for increasing values ??of the relative pressures deformation of the leaves compared to the fixed frames; 2. is then made ??to the test repeated presses, in which the frame is subjected to 50 cycles of pressure; 3 at the end of these first two tests are not allowed to degrade functional all'infisso, such for example as cause malfunction of switching devices for the opening and closing of the doors; 4. is then conducted a further test of permeability & agrave air, during which the values ??measured at a pressure of 100 Pa should be within a tolerance normalized with respect to the data initially recorded; 5. last test is carried out security, which consists in printing a single shot of very high pressure; the term of this type of test, there must be no functional damage or breakages that may cause danger to users. The various pressures used in the entire series of tests are standardized according to the class that you will be able to assign to the frame; in case of a negative result we proceed to a downgrade, while successfully re-run the test for a higher class. According to the UNI EN 12210, the fixture & ograve can be classified into 5 classes for the wind pressure (1, 2, 3, 4, 5) and in three classes for the arrow on the front (A, B, C).