corrosive effects of the drilling fluids such as 316l sintering takes place in specialized sintering equipment placing the layers of mesh under conditions of high temperatures to where the mesh metal softens sufficient for bonding for example in the range of 500 1100 degrees centigrade the process also places the mesh layers under sufficient pressure that the layers once softened are pressed together to form consistent bonding wherever the wires in a layer touch the wires in the next layer the initial layers of mesh must be compatible in terms of being capable of being sintered together and should be of similar melting and softening temperature points and similar cooling times in order that the sintering process does not cause one screen element to soften too much and deform or even anneal while another element has not yet softened sufficiently for sintering and in order that during cooling no element cools at a significantly different rate as that might cause deformation cracking or loosening of sintered bonds there is no single optimum combination of mesh sizes for mud screens as the screens used will be different depending upon drilling conditions for instance hard rock drilling typically produces fine cuttings which will require a screen with a finer surface mesh and softer rock or shale will produce cuttings which can be large and sliver shaped permitting the use of larger mesh openings in the mud screen used smaller mesh openings will also cause slower fluid flow through the screen therefore the choice of screen used in drilling operations will depend greatly upon the circumstances and environment in the borehole the mud screen needs to be of a large enough mesh to allow.